From 7f9eeaf08ec196e24484c19dae0f7b66d319b9ce Mon Sep 17 00:00:00 2001
From: rain84 <rainy_sky@mail.ru>
Date: Wed, 26 Jun 2024 22:02:48 +0300
Subject: [PATCH 01/16] feat: add 2nd ts solution to lc problem: No.0295

---
 .../README.md                                 | 38 +++++++++++++++++++
 .../README_EN.md                              | 38 +++++++++++++++++++
 .../Solution2.ts                              | 23 +++++++++++
 3 files changed, 99 insertions(+)
 create mode 100644 solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README.md b/solution/0200-0299/0295.Find Median from Data Stream/README.md
index 6d493c1a05408..44ce09bdc169e 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README.md	
@@ -422,4 +422,42 @@ public class MedianFinder {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### Solution 2. Min/max heaps
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+class MedianFinder {
+    #minQ = new MinPriorityQueue<number>();
+    #maxQ = new MaxPriorityQueue<number>();
+
+    addNum(num: number): void {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() > maxQ.size()) {
+            maxQ.enqueue(minQ.dequeue().element);
+        }
+    }
+
+    findMedian(): number {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        const median =
+            maxQ.size() === minQ.size()
+                ? (maxQ.front().element + minQ.front().element) / 2
+                : maxQ.front().element;
+
+        return median;
+    }
+}
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md
index 90732ca922234..359d346fcbfe1 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
@@ -417,4 +417,42 @@ public class MedianFinder {
 
 <!-- solution:end -->
 
+<!-- solution:start -->
+
+### Solution 2. Min/max heaps
+
+<!-- tabs:start -->
+
+#### TypeScript
+
+```ts
+class MedianFinder {
+    #minQ = new MinPriorityQueue<number>();
+    #maxQ = new MaxPriorityQueue<number>();
+
+    addNum(num: number): void {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() > maxQ.size()) {
+            maxQ.enqueue(minQ.dequeue().element);
+        }
+    }
+
+    findMedian(): number {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        const median =
+            maxQ.size() === minQ.size()
+                ? (maxQ.front().element + minQ.front().element) / 2
+                : maxQ.front().element;
+
+        return median;
+    }
+}
+```
+
+<!-- tabs:end -->
+
+<!-- solution:end -->
+
 <!-- problem:end -->
diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts b/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts
new file mode 100644
index 0000000000000..4b67cb2267685
--- /dev/null
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts	
@@ -0,0 +1,23 @@
+class MedianFinder {
+    #minQ = new MinPriorityQueue<number>();
+    #maxQ = new MaxPriorityQueue<number>();
+
+    addNum(num: number): void {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() > maxQ.size()) {
+            maxQ.enqueue(minQ.dequeue().element);
+        }
+    }
+
+    findMedian(): number {
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        const median =
+            maxQ.size() === minQ.size()
+                ? (maxQ.front().element + minQ.front().element) / 2
+                : maxQ.front().element;
+
+        return median;
+    }
+}

From 3534e198c33cdf77918e7a319e62758b519c0619 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:23:20 +0800
Subject: [PATCH 02/16] Update README.md

---
 .../README.md                                 | 383 ++++++++++--------
 1 file changed, 206 insertions(+), 177 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README.md b/solution/0200-0299/0295.Find Median from Data Stream/README.md
index 44ce09bdc169e..d9c15caab2ad3 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README.md	
@@ -72,17 +72,15 @@ medianFinder.findMedian(); // return 2.0</pre>
 
 <!-- solution:start -->
 
-### 方法一：优先队列（双堆）
+### 方法一：大小根堆（优先队列）
 
-创建大根堆、小根堆，其中：大根堆存放较小的一半元素，小根堆存放较大的一半元素。
+我们可以使用两个堆来维护所有的元素，一个小根堆 $\text{minQ}$ 和一个大根堆 $\text{maxQ}$，其中小根堆 $\text{minQ}$ 存储较大的一半，大根堆 $\text{maxQ}$ 存储较小的一半。
 
-添加元素时，先放入小根堆，然后将小根堆对顶元素弹出并放入大根堆（使得大根堆个数多 $1$）；若大小根堆元素个数差超过 $1$，则将大根堆元素弹出放入小根堆。
+调用 `addNum` 方法时，我们首先将元素加入到大根堆 $\text{maxQ}$，然后将 $\text{maxQ}$ 的堆顶元素弹出并加入到小根堆 $\text{minQ}$。如果此时 $\text{minQ}$ 的大小与 $\text{maxQ}$ 的大小差值大于 $1$，我们就将 $\text{minQ}$ 的堆顶元素弹出并加入到 $\text{maxQ}$。时间复杂度为 $O(\log n)$。
 
-取中位数时，若大根堆元素较多，取大根堆堆顶，否则取两堆顶元素和的平均值。
+调用 `findMedian` 方法时，如果 $\text{minQ}$ 的大小等于 $\text{maxQ}$ 的大小，说明元素的总数为偶数，我们就可以返回 $\text{minQ}$ 的堆顶元素与 $\text{maxQ}$ 的堆顶元素的平均值；否则，我们返回 $\text{minQ}$ 的堆顶元素。时间复杂度为 $O(1)$。
 
-**时间复杂度分析：**
-
-每次添加元素的时间复杂度为 $O(\log n)$，取中位数的时间复杂度为 $O(1)$。
+空间复杂度为 $O(n)$。其中 $n$ 为元素的个数。
 
 <!-- tabs:start -->
 
@@ -90,23 +88,20 @@ medianFinder.findMedian(); // return 2.0</pre>
 
 ```python
 class MedianFinder:
+
     def __init__(self):
-        """
-        initialize your data structure here.
-        """
-        self.h1 = []
-        self.h2 = []
+        self.minq = []
+        self.maxq = []
 
     def addNum(self, num: int) -> None:
-        heappush(self.h1, num)
-        heappush(self.h2, -heappop(self.h1))
-        if len(self.h2) - len(self.h1) > 1:
-            heappush(self.h1, -heappop(self.h2))
+        heappush(self.minq, -heappushpop(self.maxq, -num))
+        if len(self.minq) - len(self.maxq) > 1:
+            heappush(self.maxq, -heappop(self.minq))
 
     def findMedian(self) -> float:
-        if len(self.h2) > len(self.h1):
-            return -self.h2[0]
-        return (self.h1[0] - self.h2[0]) / 2
+        if len(self.minq) == len(self.maxq):
+            return (self.minq[0] - self.maxq[0]) / 2
+        return self.minq[0]
 
 
 # Your MedianFinder object will be instantiated and called as such:
@@ -119,26 +114,23 @@ class MedianFinder:
 
 ```java
 class MedianFinder {
-    private PriorityQueue<Integer> q1 = new PriorityQueue<>();
-    private PriorityQueue<Integer> q2 = new PriorityQueue<>(Collections.reverseOrder());
+    private PriorityQueue<Integer> minQ = new PriorityQueue<>();
+    private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
-    /** initialize your data structure here. */
     public MedianFinder() {
+
     }
 
     public void addNum(int num) {
-        q1.offer(num);
-        q2.offer(q1.poll());
-        if (q2.size() - q1.size() > 1) {
-            q1.offer(q2.poll());
+        maxQ.offer(num);
+        minQ.offer(maxQ.poll());
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.offer(minQ.poll());
         }
     }
 
     public double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.peek();
-        }
-        return (q1.peek() + q2.peek()) * 1.0 / 2;
+        return minQ.size() == maxQ.size() ? (minQ.peek() + maxQ.peek()) / 2.0 : minQ.peek();
     }
 }
 
@@ -155,30 +147,27 @@ class MedianFinder {
 ```cpp
 class MedianFinder {
 public:
-    /** initialize your data structure here. */
     MedianFinder() {
     }
 
     void addNum(int num) {
-        q1.push(num);
-        q2.push(q1.top());
-        q1.pop();
-        if (q2.size() - q1.size() > 1) {
-            q1.push(q2.top());
-            q2.pop();
+        maxQ.push(num);
+        minQ.push(maxQ.top());
+        maxQ.pop();
+
+        if (minQ.size() > maxQ.size() + 1) {
+            maxQ.push(minQ.top());
+            minQ.pop();
         }
     }
 
     double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.top();
-        }
-        return (double) (q1.top() + q2.top()) / 2;
+        return minQ.size() == maxQ.size() ? (minQ.top() + maxQ.top()) / 2.0 : minQ.top();
     }
 
 private:
-    priority_queue<int, vector<int>, greater<int>> q1;
-    priority_queue<int> q2;
+    priority_queue<int> maxQ;
+    priority_queue<int, vector<int>, greater<int>> minQ;
 };
 
 /**
@@ -193,37 +182,31 @@ private:
 
 ```go
 type MedianFinder struct {
-	q1 hp
-	q2 hp
+	minq hp
+	maxq hp
 }
 
-/** initialize your data structure here. */
 func Constructor() MedianFinder {
 	return MedianFinder{hp{}, hp{}}
 }
 
 func (this *MedianFinder) AddNum(num int) {
-	heap.Push(&this.q1, num)
-	heap.Push(&this.q2, -heap.Pop(&this.q1).(int))
-	if this.q2.Len()-this.q1.Len() > 1 {
-		heap.Push(&this.q1, -heap.Pop(&this.q2).(int))
+	minq, maxq := &this.minq, &this.maxq
+	heap.Push(maxq, -num)
+	heap.Push(minq, -heap.Pop(maxq).(int))
+	if minq.Len()-maxq.Len() > 1 {
+		heap.Push(maxq, -heap.Pop(minq).(int))
 	}
 }
 
 func (this *MedianFinder) FindMedian() float64 {
-	if this.q2.Len() > this.q1.Len() {
-		return -float64(this.q2.IntSlice[0])
+	minq, maxq := this.minq, this.maxq
+	if minq.Len() == maxq.Len() {
+		return float64(minq.IntSlice[0]-maxq.IntSlice[0]) / 2
 	}
-	return float64(this.q1.IntSlice[0]-this.q2.IntSlice[0]) / 2.0
+	return float64(minq.IntSlice[0])
 }
 
-/**
- * Your MedianFinder object will be instantiated and called as such:
- * obj := Constructor();
- * obj.AddNum(num);
- * param_2 := obj.FindMedian();
- */
-
 type hp struct{ sort.IntSlice }
 
 func (h hp) Less(i, j int) bool { return h.IntSlice[i] < h.IntSlice[j] }
@@ -234,40 +217,37 @@ func (h *hp) Pop() any {
 	h.IntSlice = a[:len(a)-1]
 	return v
 }
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * obj := Constructor();
+ * obj.AddNum(num);
+ * param_2 := obj.FindMedian();
+ */
 ```
 
 #### TypeScript
 
 ```ts
 class MedianFinder {
-    private nums: number[];
-
-    constructor() {
-        this.nums = [];
-    }
+    #minQ = new MinPriorityQueue();
+    #maxQ = new MaxPriorityQueue();
 
     addNum(num: number): void {
-        const { nums } = this;
-        let l = 0;
-        let r = nums.length;
-        while (l < r) {
-            const mid = (l + r) >>> 1;
-            if (nums[mid] < num) {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.enqueue(minQ.dequeue().element);
         }
-        nums.splice(l, 0, num);
     }
 
     findMedian(): number {
-        const { nums } = this;
-        const n = nums.length;
-        if ((n & 1) === 1) {
-            return nums[n >> 1];
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        if (minQ.size() === maxQ.size()) {
+            return (minQ.front().element + maxQ.front().element) / 2;
         }
-        return (nums[n >> 1] + nums[(n >> 1) - 1]) / 2;
+        return minQ.front().element;
     }
 }
 
@@ -282,40 +262,39 @@ class MedianFinder {
 #### Rust
 
 ```rust
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
 struct MedianFinder {
-    nums: Vec<i32>,
+    minQ: BinaryHeap<Reverse<i32>>,
+    maxQ: BinaryHeap<i32>,
 }
 
-/**
- * `&self` means the method takes an immutable reference.
- * If you need a mutable reference, change it to `&mut self` instead.
- */
 impl MedianFinder {
-    /** initialize your data structure here. */
     fn new() -> Self {
-        Self { nums: Vec::new() }
+        MedianFinder {
+            minQ: BinaryHeap::new(),
+            maxQ: BinaryHeap::new(),
+        }
     }
 
     fn add_num(&mut self, num: i32) {
-        let mut l = 0;
-        let mut r = self.nums.len();
-        while l < r {
-            let mid = (l + r) >> 1;
-            if self.nums[mid] < num {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        self.maxQ.push(num);
+        self.minQ.push(Reverse(self.maxQ.pop().unwrap()));
+
+        if self.minQ.len() > self.maxQ.len() + 1 {
+            self.maxQ.push(self.minQ.pop().unwrap().0);
         }
-        self.nums.insert(l, num);
     }
 
     fn find_median(&self) -> f64 {
-        let n = self.nums.len();
-        if (n & 1) == 1 {
-            return f64::from(self.nums[n >> 1]);
+        if self.minQ.len() == self.maxQ.len() {
+            let min_top = self.minQ.peek().unwrap().0;
+            let max_top = *self.maxQ.peek().unwrap();
+            (min_top + max_top) as f64 / 2.0
+        } else {
+            self.minQ.peek().unwrap().0 as f64
         }
-        f64::from(self.nums[n >> 1] + self.nums[(n >> 1) - 1]) / 2.0
     }
 }
 ```
@@ -323,11 +302,9 @@ impl MedianFinder {
 #### JavaScript
 
 ```js
-/**
- * initialize your data structure here.
- */
 var MedianFinder = function () {
-    this.val = [];
+    this.minQ = new MinPriorityQueue();
+    this.maxQ = new MaxPriorityQueue();
 };
 
 /**
@@ -335,78 +312,52 @@ var MedianFinder = function () {
  * @return {void}
  */
 MedianFinder.prototype.addNum = function (num) {
-    let left = 0;
-    let right = this.val.length;
-    while (left < right) {
-        let mid = left + ~~((right - left) / 2);
-        if (num > this.val[mid]) {
-            left = mid + 1;
-        } else {
-            right = mid;
-        }
+    this.maxQ.enqueue(num);
+    this.minQ.enqueue(this.maxQ.dequeue().element);
+    if (this.minQ.size() - this.maxQ.size() > 1) {
+        this.maxQ.enqueue(this.minQ.dequeue().element);
     }
-    this.val.splice(left, 0, num);
 };
 
 /**
  * @return {number}
  */
 MedianFinder.prototype.findMedian = function () {
-    let mid = ~~(this.val.length / 2);
-    return this.val.length % 2 ? this.val[mid] : (this.val[mid - 1] + this.val[mid]) / 2;
+    if (this.minQ.size() === this.maxQ.size()) {
+        return (this.minQ.front().element + this.maxQ.front().element) / 2;
+    }
+    return this.minQ.front().element;
 };
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * var obj = new MedianFinder()
+ * obj.addNum(num)
+ * var param_2 = obj.findMedian()
+ */
 ```
 
 #### C#
 
 ```cs
 public class MedianFinder {
-    private List<int> nums;
-    private int curIndex;
+    private PriorityQueue<int, int> minQ = new PriorityQueue<int, int>();
+    private PriorityQueue<int, int> maxQ = new PriorityQueue<int, int>(Comparer<int>.Create((a, b) => b.CompareTo(a)));
 
-    /** initialize your data structure here. */
     public MedianFinder() {
-        nums = new List<int>();
-    }
 
-    private int FindIndex(int val) {
-        int left = 0;
-        int right = nums.Count - 1;
-        while (left <= right) {
-            int mid = left + (right - left) / 2;
-            if (val > nums[mid]) {
-                left = mid + 1;
-            } else {
-                right = mid - 1;
-            }
-        }
-        return left;
     }
 
     public void AddNum(int num) {
-        if (nums.Count == 0) {
-            nums.Add(num);
-            curIndex = 0;
-        } else {
-            curIndex = FindIndex(num);
-            if (curIndex == nums.Count) {
-                nums.Add(num);
-            } else {
-                nums.Insert(curIndex, num);
-            }
+        maxQ.Enqueue(num, num);
+        minQ.Enqueue(maxQ.Peek(), maxQ.Dequeue());
+        if (minQ.Count > maxQ.Count + 1) {
+            maxQ.Enqueue(minQ.Peek(), minQ.Dequeue());
         }
     }
 
     public double FindMedian() {
-        if (nums.Count % 2 == 1) {
-            return (double)nums[nums.Count / 2];
-        } else {
-            if (nums.Count == 0) {
-                return 0;
-            } else {
-                return (double) (nums[nums.Count / 2 - 1] + nums[nums.Count / 2]) / 2;
-            }
-        }
+        return minQ.Count == maxQ.Count ? (minQ.Peek() + maxQ.Peek()) / 2.0 : minQ.Peek();
     }
 }
 
@@ -418,42 +369,120 @@ public class MedianFinder {
  */
 ```
 
-<!-- tabs:end -->
+#### Swift
 
-<!-- solution:end -->
+```swift
+class MedianFinder {
+    private var minQ = Heap<Int>(sort: <)
+    private var maxQ = Heap<Int>(sort: >)
 
-<!-- solution:start -->
+    init() {
+    }
 
-### Solution 2. Min/max heaps
+    func addNum(_ num: Int) {
+        maxQ.insert(num)
+        minQ.insert(maxQ.remove()!)
+        if maxQ.count < minQ.count {
+            maxQ.insert(minQ.remove()!)
+        }
+    }
 
-<!-- tabs:start -->
+    func findMedian() -> Double {
+        if maxQ.count > minQ.count {
+            return Double(maxQ.peek()!)
+        }
+        return (Double(maxQ.peek()!) + Double(minQ.peek()!)) / 2.0
+    }
+}
 
-#### TypeScript
+struct Heap<T> {
+    var elements: [T]
+    let sort: (T, T) -> Bool
 
-```ts
-class MedianFinder {
-    #minQ = new MinPriorityQueue<number>();
-    #maxQ = new MaxPriorityQueue<number>();
+    init(sort: @escaping (T, T) -> Bool, elements: [T] = []) {
+        self.sort = sort
+        self.elements = elements
+        if !elements.isEmpty {
+            for i in stride(from: elements.count / 2 - 1, through: 0, by: -1) {
+                siftDown(from: i)
+            }
+        }
+    }
 
-    addNum(num: number): void {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        maxQ.enqueue(num);
-        minQ.enqueue(maxQ.dequeue().element);
-        if (minQ.size() > maxQ.size()) {
-            maxQ.enqueue(minQ.dequeue().element);
+    var isEmpty: Bool {
+        return elements.isEmpty
+    }
+
+    var count: Int {
+        return elements.count
+    }
+
+    func peek() -> T? {
+        return elements.first
+    }
+
+    mutating func insert(_ value: T) {
+        elements.append(value)
+        siftUp(from: elements.count - 1)
+    }
+
+    mutating func remove() -> T? {
+        guard !elements.isEmpty else { return nil }
+        elements.swapAt(0, elements.count - 1)
+        let removedValue = elements.removeLast()
+        siftDown(from: 0)
+        return removedValue
+    }
+
+    private mutating func siftUp(from index: Int) {
+        var child = index
+        var parent = parentIndex(ofChildAt: child)
+        while child > 0 && sort(elements[child], elements[parent]) {
+            elements.swapAt(child, parent)
+            child = parent
+            parent = parentIndex(ofChildAt: child)
         }
     }
 
-    findMedian(): number {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        const median =
-            maxQ.size() === minQ.size()
-                ? (maxQ.front().element + minQ.front().element) / 2
-                : maxQ.front().element;
+    private mutating func siftDown(from index: Int) {
+        var parent = index
+        while true {
+            let left = leftChildIndex(ofParentAt: parent)
+            let right = rightChildIndex(ofParentAt: parent)
+            var candidate = parent
+            if left < count && sort(elements[left], elements[candidate]) {
+                candidate = left
+            }
+            if right < count && sort(elements[right], elements[candidate]) {
+                candidate = right
+            }
+            if candidate == parent {
+                return
+            }
+            elements.swapAt(parent, candidate)
+            parent = candidate
+        }
+    }
+
+    private func parentIndex(ofChildAt index: Int) -> Int {
+        return (index - 1) / 2
+    }
+
+    private func leftChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 1
+    }
 
-        return median;
+    private func rightChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 2
     }
 }
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * let obj = MedianFinder()
+ * obj.addNum(num)
+ * let ret_2: Double = obj.findMedian()
+ */
 ```
 
 <!-- tabs:end -->

From 59cd174ee7f9d683e3995e4107bc4ff290b9109f Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:23:31 +0800
Subject: [PATCH 03/16] Update README_EN.md

---
 .../README_EN.md                              | 381 ++++++++++--------
 1 file changed, 210 insertions(+), 171 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md
index 359d346fcbfe1..957d11c6a5a67 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
@@ -77,7 +77,15 @@ medianFinder.findMedian(); // return 2.0
 
 <!-- solution:start -->
 
-### Solution 1
+### Solution 1: Min Heap and Max Heap (Priority Queue)
+
+We can use two heaps to maintain all the elements, a min heap $\text{minQ}$ and a max heap $\text{maxQ}$, where the min heap $\text{minQ}$ stores the larger half, and the max heap $\text{maxQ}$ stores the smaller half.
+
+When calling the `addNum` method, we first add the element to the max heap $\text{maxQ}$, then pop the top element of $\text{maxQ}$ and add it to the min heap $\text{minQ}$. If at this time the size difference between $\text{minQ}$ and $\text{maxQ}$ is greater than $1$, we pop the top element of $\text{minQ}$ and add it to $\text{maxQ}$. The time complexity is $O(\log n)$.
+
+When calling the `findMedian` method, if the size of $\text{minQ}$ is equal to the size of $\text{maxQ}$, it means the total number of elements is even, and we can return the average value of the top elements of $\text{minQ}$ and $\text{maxQ}$; otherwise, we return the top element of $\text{minQ}$. The time complexity is $O(1)$.
+
+The space complexity is $O(n)$, where $n$ is the number of elements.
 
 <!-- tabs:start -->
 
@@ -85,23 +93,20 @@ medianFinder.findMedian(); // return 2.0
 
 ```python
 class MedianFinder:
+
     def __init__(self):
-        """
-        initialize your data structure here.
-        """
-        self.h1 = []
-        self.h2 = []
+        self.minq = []
+        self.maxq = []
 
     def addNum(self, num: int) -> None:
-        heappush(self.h1, num)
-        heappush(self.h2, -heappop(self.h1))
-        if len(self.h2) - len(self.h1) > 1:
-            heappush(self.h1, -heappop(self.h2))
+        heappush(self.minq, -heappushpop(self.maxq, -num))
+        if len(self.minq) - len(self.maxq) > 1:
+            heappush(self.maxq, -heappop(self.minq))
 
     def findMedian(self) -> float:
-        if len(self.h2) > len(self.h1):
-            return -self.h2[0]
-        return (self.h1[0] - self.h2[0]) / 2
+        if len(self.minq) == len(self.maxq):
+            return (self.minq[0] - self.maxq[0]) / 2
+        return self.minq[0]
 
 
 # Your MedianFinder object will be instantiated and called as such:
@@ -114,26 +119,23 @@ class MedianFinder:
 
 ```java
 class MedianFinder {
-    private PriorityQueue<Integer> q1 = new PriorityQueue<>();
-    private PriorityQueue<Integer> q2 = new PriorityQueue<>(Collections.reverseOrder());
+    private PriorityQueue<Integer> minQ = new PriorityQueue<>();
+    private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
-    /** initialize your data structure here. */
     public MedianFinder() {
+
     }
 
     public void addNum(int num) {
-        q1.offer(num);
-        q2.offer(q1.poll());
-        if (q2.size() - q1.size() > 1) {
-            q1.offer(q2.poll());
+        maxQ.offer(num);
+        minQ.offer(maxQ.poll());
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.offer(minQ.poll());
         }
     }
 
     public double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.peek();
-        }
-        return (q1.peek() + q2.peek()) * 1.0 / 2;
+        return minQ.size() == maxQ.size() ? (minQ.peek() + maxQ.peek()) / 2.0 : minQ.peek();
     }
 }
 
@@ -150,30 +152,27 @@ class MedianFinder {
 ```cpp
 class MedianFinder {
 public:
-    /** initialize your data structure here. */
     MedianFinder() {
     }
 
     void addNum(int num) {
-        q1.push(num);
-        q2.push(q1.top());
-        q1.pop();
-        if (q2.size() - q1.size() > 1) {
-            q1.push(q2.top());
-            q2.pop();
+        maxQ.push(num);
+        minQ.push(maxQ.top());
+        maxQ.pop();
+
+        if (minQ.size() > maxQ.size() + 1) {
+            maxQ.push(minQ.top());
+            minQ.pop();
         }
     }
 
     double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.top();
-        }
-        return (double) (q1.top() + q2.top()) / 2;
+        return minQ.size() == maxQ.size() ? (minQ.top() + maxQ.top()) / 2.0 : minQ.top();
     }
 
 private:
-    priority_queue<int, vector<int>, greater<int>> q1;
-    priority_queue<int> q2;
+    priority_queue<int> maxQ;
+    priority_queue<int, vector<int>, greater<int>> minQ;
 };
 
 /**
@@ -188,37 +187,31 @@ private:
 
 ```go
 type MedianFinder struct {
-	q1 hp
-	q2 hp
+	minq hp
+	maxq hp
 }
 
-/** initialize your data structure here. */
 func Constructor() MedianFinder {
 	return MedianFinder{hp{}, hp{}}
 }
 
 func (this *MedianFinder) AddNum(num int) {
-	heap.Push(&this.q1, num)
-	heap.Push(&this.q2, -heap.Pop(&this.q1).(int))
-	if this.q2.Len()-this.q1.Len() > 1 {
-		heap.Push(&this.q1, -heap.Pop(&this.q2).(int))
+	minq, maxq := &this.minq, &this.maxq
+	heap.Push(maxq, -num)
+	heap.Push(minq, -heap.Pop(maxq).(int))
+	if minq.Len()-maxq.Len() > 1 {
+		heap.Push(maxq, -heap.Pop(minq).(int))
 	}
 }
 
 func (this *MedianFinder) FindMedian() float64 {
-	if this.q2.Len() > this.q1.Len() {
-		return -float64(this.q2.IntSlice[0])
+	minq, maxq := this.minq, this.maxq
+	if minq.Len() == maxq.Len() {
+		return float64(minq.IntSlice[0]-maxq.IntSlice[0]) / 2
 	}
-	return float64(this.q1.IntSlice[0]-this.q2.IntSlice[0]) / 2.0
+	return float64(minq.IntSlice[0])
 }
 
-/**
- * Your MedianFinder object will be instantiated and called as such:
- * obj := Constructor();
- * obj.AddNum(num);
- * param_2 := obj.FindMedian();
- */
-
 type hp struct{ sort.IntSlice }
 
 func (h hp) Less(i, j int) bool { return h.IntSlice[i] < h.IntSlice[j] }
@@ -229,40 +222,37 @@ func (h *hp) Pop() any {
 	h.IntSlice = a[:len(a)-1]
 	return v
 }
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * obj := Constructor();
+ * obj.AddNum(num);
+ * param_2 := obj.FindMedian();
+ */
 ```
 
 #### TypeScript
 
 ```ts
 class MedianFinder {
-    private nums: number[];
-
-    constructor() {
-        this.nums = [];
-    }
+    #minQ = new MinPriorityQueue();
+    #maxQ = new MaxPriorityQueue();
 
     addNum(num: number): void {
-        const { nums } = this;
-        let l = 0;
-        let r = nums.length;
-        while (l < r) {
-            const mid = (l + r) >>> 1;
-            if (nums[mid] < num) {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.enqueue(minQ.dequeue().element);
         }
-        nums.splice(l, 0, num);
     }
 
     findMedian(): number {
-        const { nums } = this;
-        const n = nums.length;
-        if ((n & 1) === 1) {
-            return nums[n >> 1];
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        if (minQ.size() === maxQ.size()) {
+            return (minQ.front().element + maxQ.front().element) / 2;
         }
-        return (nums[n >> 1] + nums[(n >> 1) - 1]) / 2;
+        return minQ.front().element;
     }
 }
 
@@ -277,40 +267,39 @@ class MedianFinder {
 #### Rust
 
 ```rust
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
 struct MedianFinder {
-    nums: Vec<i32>,
+    minQ: BinaryHeap<Reverse<i32>>,
+    maxQ: BinaryHeap<i32>,
 }
 
-/**
- * `&self` means the method takes an immutable reference.
- * If you need a mutable reference, change it to `&mut self` instead.
- */
 impl MedianFinder {
-    /** initialize your data structure here. */
     fn new() -> Self {
-        Self { nums: Vec::new() }
+        MedianFinder {
+            minQ: BinaryHeap::new(),
+            maxQ: BinaryHeap::new(),
+        }
     }
 
     fn add_num(&mut self, num: i32) {
-        let mut l = 0;
-        let mut r = self.nums.len();
-        while l < r {
-            let mid = (l + r) >> 1;
-            if self.nums[mid] < num {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        self.maxQ.push(num);
+        self.minQ.push(Reverse(self.maxQ.pop().unwrap()));
+
+        if self.minQ.len() > self.maxQ.len() + 1 {
+            self.maxQ.push(self.minQ.pop().unwrap().0);
         }
-        self.nums.insert(l, num);
     }
 
     fn find_median(&self) -> f64 {
-        let n = self.nums.len();
-        if (n & 1) == 1 {
-            return f64::from(self.nums[n >> 1]);
+        if self.minQ.len() == self.maxQ.len() {
+            let min_top = self.minQ.peek().unwrap().0;
+            let max_top = *self.maxQ.peek().unwrap();
+            (min_top + max_top) as f64 / 2.0
+        } else {
+            self.minQ.peek().unwrap().0 as f64
         }
-        f64::from(self.nums[n >> 1] + self.nums[(n >> 1) - 1]) / 2.0
     }
 }
 ```
@@ -318,11 +307,9 @@ impl MedianFinder {
 #### JavaScript
 
 ```js
-/**
- * initialize your data structure here.
- */
 var MedianFinder = function () {
-    this.val = [];
+    this.minQ = new MinPriorityQueue();
+    this.maxQ = new MaxPriorityQueue();
 };
 
 /**
@@ -330,78 +317,52 @@ var MedianFinder = function () {
  * @return {void}
  */
 MedianFinder.prototype.addNum = function (num) {
-    let left = 0;
-    let right = this.val.length;
-    while (left < right) {
-        let mid = left + ~~((right - left) / 2);
-        if (num > this.val[mid]) {
-            left = mid + 1;
-        } else {
-            right = mid;
-        }
+    this.maxQ.enqueue(num);
+    this.minQ.enqueue(this.maxQ.dequeue().element);
+    if (this.minQ.size() - this.maxQ.size() > 1) {
+        this.maxQ.enqueue(this.minQ.dequeue().element);
     }
-    this.val.splice(left, 0, num);
 };
 
 /**
  * @return {number}
  */
 MedianFinder.prototype.findMedian = function () {
-    let mid = ~~(this.val.length / 2);
-    return this.val.length % 2 ? this.val[mid] : (this.val[mid - 1] + this.val[mid]) / 2;
+    if (this.minQ.size() === this.maxQ.size()) {
+        return (this.minQ.front().element + this.maxQ.front().element) / 2;
+    }
+    return this.minQ.front().element;
 };
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * var obj = new MedianFinder()
+ * obj.addNum(num)
+ * var param_2 = obj.findMedian()
+ */
 ```
 
 #### C#
 
 ```cs
 public class MedianFinder {
-    private List<int> nums;
-    private int curIndex;
+    private PriorityQueue<int, int> minQ = new PriorityQueue<int, int>();
+    private PriorityQueue<int, int> maxQ = new PriorityQueue<int, int>(Comparer<int>.Create((a, b) => b.CompareTo(a)));
 
-    /** initialize your data structure here. */
     public MedianFinder() {
-        nums = new List<int>();
-    }
 
-    private int FindIndex(int val) {
-        int left = 0;
-        int right = nums.Count - 1;
-        while (left <= right) {
-            int mid = left + (right - left) / 2;
-            if (val > nums[mid]) {
-                left = mid + 1;
-            } else {
-                right = mid - 1;
-            }
-        }
-        return left;
     }
 
     public void AddNum(int num) {
-        if (nums.Count == 0) {
-            nums.Add(num);
-            curIndex = 0;
-        } else {
-            curIndex = FindIndex(num);
-            if (curIndex == nums.Count) {
-                nums.Add(num);
-            } else {
-                nums.Insert(curIndex, num);
-            }
+        maxQ.Enqueue(num, num);
+        minQ.Enqueue(maxQ.Peek(), maxQ.Dequeue());
+        if (minQ.Count > maxQ.Count + 1) {
+            maxQ.Enqueue(minQ.Peek(), minQ.Dequeue());
         }
     }
 
     public double FindMedian() {
-        if (nums.Count % 2 == 1) {
-            return (double)nums[nums.Count / 2];
-        } else {
-            if (nums.Count == 0) {
-                return 0;
-            } else {
-                return (double) (nums[nums.Count / 2 - 1] + nums[nums.Count / 2]) / 2;
-            }
-        }
+        return minQ.Count == maxQ.Count ? (minQ.Peek() + maxQ.Peek()) / 2.0 : minQ.Peek();
     }
 }
 
@@ -413,42 +374,120 @@ public class MedianFinder {
  */
 ```
 
-<!-- tabs:end -->
+#### Swift
 
-<!-- solution:end -->
+```swift
+class MedianFinder {
+    private var minQ = Heap<Int>(sort: <)
+    private var maxQ = Heap<Int>(sort: >)
 
-<!-- solution:start -->
+    init() {
+    }
 
-### Solution 2. Min/max heaps
+    func addNum(_ num: Int) {
+        maxQ.insert(num)
+        minQ.insert(maxQ.remove()!)
+        if maxQ.count < minQ.count {
+            maxQ.insert(minQ.remove()!)
+        }
+    }
 
-<!-- tabs:start -->
+    func findMedian() -> Double {
+        if maxQ.count > minQ.count {
+            return Double(maxQ.peek()!)
+        }
+        return (Double(maxQ.peek()!) + Double(minQ.peek()!)) / 2.0
+    }
+}
 
-#### TypeScript
+struct Heap<T> {
+    var elements: [T]
+    let sort: (T, T) -> Bool
 
-```ts
-class MedianFinder {
-    #minQ = new MinPriorityQueue<number>();
-    #maxQ = new MaxPriorityQueue<number>();
+    init(sort: @escaping (T, T) -> Bool, elements: [T] = []) {
+        self.sort = sort
+        self.elements = elements
+        if !elements.isEmpty {
+            for i in stride(from: elements.count / 2 - 1, through: 0, by: -1) {
+                siftDown(from: i)
+            }
+        }
+    }
 
-    addNum(num: number): void {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        maxQ.enqueue(num);
-        minQ.enqueue(maxQ.dequeue().element);
-        if (minQ.size() > maxQ.size()) {
-            maxQ.enqueue(minQ.dequeue().element);
+    var isEmpty: Bool {
+        return elements.isEmpty
+    }
+
+    var count: Int {
+        return elements.count
+    }
+
+    func peek() -> T? {
+        return elements.first
+    }
+
+    mutating func insert(_ value: T) {
+        elements.append(value)
+        siftUp(from: elements.count - 1)
+    }
+
+    mutating func remove() -> T? {
+        guard !elements.isEmpty else { return nil }
+        elements.swapAt(0, elements.count - 1)
+        let removedValue = elements.removeLast()
+        siftDown(from: 0)
+        return removedValue
+    }
+
+    private mutating func siftUp(from index: Int) {
+        var child = index
+        var parent = parentIndex(ofChildAt: child)
+        while child > 0 && sort(elements[child], elements[parent]) {
+            elements.swapAt(child, parent)
+            child = parent
+            parent = parentIndex(ofChildAt: child)
         }
     }
 
-    findMedian(): number {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        const median =
-            maxQ.size() === minQ.size()
-                ? (maxQ.front().element + minQ.front().element) / 2
-                : maxQ.front().element;
+    private mutating func siftDown(from index: Int) {
+        var parent = index
+        while true {
+            let left = leftChildIndex(ofParentAt: parent)
+            let right = rightChildIndex(ofParentAt: parent)
+            var candidate = parent
+            if left < count && sort(elements[left], elements[candidate]) {
+                candidate = left
+            }
+            if right < count && sort(elements[right], elements[candidate]) {
+                candidate = right
+            }
+            if candidate == parent {
+                return
+            }
+            elements.swapAt(parent, candidate)
+            parent = candidate
+        }
+    }
 
-        return median;
+    private func parentIndex(ofChildAt index: Int) -> Int {
+        return (index - 1) / 2
+    }
+
+    private func leftChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 1
+    }
+
+    private func rightChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 2
     }
 }
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * let obj = MedianFinder()
+ * obj.addNum(num)
+ * let ret_2: Double = obj.findMedian()
+ */
 ```
 
 <!-- tabs:end -->

From 93af2808b062bd1b60eff1bb21922f268108959c Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:23:41 +0800
Subject: [PATCH 04/16] Delete solution/0200-0299/0295.Find Median from Data
 Stream/Solution2.ts

---
 .../Solution2.ts                              | 23 -------------------
 1 file changed, 23 deletions(-)
 delete mode 100644 solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts b/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts
deleted file mode 100644
index 4b67cb2267685..0000000000000
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution2.ts	
+++ /dev/null
@@ -1,23 +0,0 @@
-class MedianFinder {
-    #minQ = new MinPriorityQueue<number>();
-    #maxQ = new MaxPriorityQueue<number>();
-
-    addNum(num: number): void {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        maxQ.enqueue(num);
-        minQ.enqueue(maxQ.dequeue().element);
-        if (minQ.size() > maxQ.size()) {
-            maxQ.enqueue(minQ.dequeue().element);
-        }
-    }
-
-    findMedian(): number {
-        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
-        const median =
-            maxQ.size() === minQ.size()
-                ? (maxQ.front().element + minQ.front().element) / 2
-                : maxQ.front().element;
-
-        return median;
-    }
-}

From 6e38e482f1c96e6ecf40729785cc7405f44c808e Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:24:13 +0800
Subject: [PATCH 05/16] Update Solution.py

---
 .../Solution.py                               | 21 ++++++++-----------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.py b/solution/0200-0299/0295.Find Median from Data Stream/Solution.py
index 3eb1703cc52f1..0b61b5b78e1c6 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.py	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.py	
@@ -1,21 +1,18 @@
 class MedianFinder:
+
     def __init__(self):
-        """
-        initialize your data structure here.
-        """
-        self.h1 = []
-        self.h2 = []
+        self.minq = []
+        self.maxq = []
 
     def addNum(self, num: int) -> None:
-        heappush(self.h1, num)
-        heappush(self.h2, -heappop(self.h1))
-        if len(self.h2) - len(self.h1) > 1:
-            heappush(self.h1, -heappop(self.h2))
+        heappush(self.minq, -heappushpop(self.maxq, -num))
+        if len(self.minq) - len(self.maxq) > 1:
+            heappush(self.maxq, -heappop(self.minq))
 
     def findMedian(self) -> float:
-        if len(self.h2) > len(self.h1):
-            return -self.h2[0]
-        return (self.h1[0] - self.h2[0]) / 2
+        if len(self.minq) == len(self.maxq):
+            return (self.minq[0] - self.maxq[0]) / 2
+        return self.minq[0]
 
 
 # Your MedianFinder object will be instantiated and called as such:

From 816af1ad951802c02a560a793fe891844c6fa596 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:24:24 +0800
Subject: [PATCH 06/16] Update Solution.java

---
 .../Solution.java                             | 21 ++++++++-----------
 1 file changed, 9 insertions(+), 12 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.java b/solution/0200-0299/0295.Find Median from Data Stream/Solution.java
index 67cba760f5d1f..c0b04faf7af10 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.java	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.java	
@@ -1,24 +1,21 @@
 class MedianFinder {
-    private PriorityQueue<Integer> q1 = new PriorityQueue<>();
-    private PriorityQueue<Integer> q2 = new PriorityQueue<>(Collections.reverseOrder());
+    private PriorityQueue<Integer> minQ = new PriorityQueue<>();
+    private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
-    /** initialize your data structure here. */
     public MedianFinder() {
+
     }
 
     public void addNum(int num) {
-        q1.offer(num);
-        q2.offer(q1.poll());
-        if (q2.size() - q1.size() > 1) {
-            q1.offer(q2.poll());
+        maxQ.offer(num);
+        minQ.offer(maxQ.poll());
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.offer(minQ.poll());
         }
     }
 
     public double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.peek();
-        }
-        return (q1.peek() + q2.peek()) * 1.0 / 2;
+        return minQ.size() == maxQ.size() ? (minQ.peek() + maxQ.peek()) / 2.0 : minQ.peek();
     }
 }
 
@@ -27,4 +24,4 @@ public double findMedian() {
  * MedianFinder obj = new MedianFinder();
  * obj.addNum(num);
  * double param_2 = obj.findMedian();
- */
\ No newline at end of file
+ */

From c5636389343d19df11d0e409daecc43e9bf61e0e Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:24:32 +0800
Subject: [PATCH 07/16] Update Solution.cpp

---
 .../Solution.cpp                              | 25 ++++++++-----------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.cpp b/solution/0200-0299/0295.Find Median from Data Stream/Solution.cpp
index 4e65d4c2bd94f..4db5d9a118f29 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.cpp	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.cpp	
@@ -1,29 +1,26 @@
 class MedianFinder {
 public:
-    /** initialize your data structure here. */
     MedianFinder() {
     }
 
     void addNum(int num) {
-        q1.push(num);
-        q2.push(q1.top());
-        q1.pop();
-        if (q2.size() - q1.size() > 1) {
-            q1.push(q2.top());
-            q2.pop();
+        maxQ.push(num);
+        minQ.push(maxQ.top());
+        maxQ.pop();
+
+        if (minQ.size() > maxQ.size() + 1) {
+            maxQ.push(minQ.top());
+            minQ.pop();
         }
     }
 
     double findMedian() {
-        if (q2.size() > q1.size()) {
-            return q2.top();
-        }
-        return (double) (q1.top() + q2.top()) / 2;
+        return minQ.size() == maxQ.size() ? (minQ.top() + maxQ.top()) / 2.0 : minQ.top();
     }
 
 private:
-    priority_queue<int, vector<int>, greater<int>> q1;
-    priority_queue<int> q2;
+    priority_queue<int> maxQ;
+    priority_queue<int, vector<int>, greater<int>> minQ;
 };
 
 /**
@@ -31,4 +28,4 @@ class MedianFinder {
  * MedianFinder* obj = new MedianFinder();
  * obj->addNum(num);
  * double param_2 = obj->findMedian();
- */
\ No newline at end of file
+ */

From 05745f605d24696c9b015de396a2bc9db19ca1a1 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:24:40 +0800
Subject: [PATCH 08/16] Update Solution.go

---
 .../Solution.go                               | 37 ++++++++++---------
 1 file changed, 19 insertions(+), 18 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.go b/solution/0200-0299/0295.Find Median from Data Stream/Solution.go
index 08bef8dd85dc0..5da36e5deebd5 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.go	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.go	
@@ -1,35 +1,29 @@
 type MedianFinder struct {
-	q1 hp
-	q2 hp
+	minq hp
+	maxq hp
 }
 
-/** initialize your data structure here. */
 func Constructor() MedianFinder {
 	return MedianFinder{hp{}, hp{}}
 }
 
 func (this *MedianFinder) AddNum(num int) {
-	heap.Push(&this.q1, num)
-	heap.Push(&this.q2, -heap.Pop(&this.q1).(int))
-	if this.q2.Len()-this.q1.Len() > 1 {
-		heap.Push(&this.q1, -heap.Pop(&this.q2).(int))
+	minq, maxq := &this.minq, &this.maxq
+	heap.Push(maxq, -num)
+	heap.Push(minq, -heap.Pop(maxq).(int))
+	if minq.Len()-maxq.Len() > 1 {
+		heap.Push(maxq, -heap.Pop(minq).(int))
 	}
 }
 
 func (this *MedianFinder) FindMedian() float64 {
-	if this.q2.Len() > this.q1.Len() {
-		return -float64(this.q2.IntSlice[0])
+	minq, maxq := this.minq, this.maxq
+	if minq.Len() == maxq.Len() {
+		return float64(minq.IntSlice[0]-maxq.IntSlice[0]) / 2
 	}
-	return float64(this.q1.IntSlice[0]-this.q2.IntSlice[0]) / 2.0
+	return float64(minq.IntSlice[0])
 }
 
-/**
- * Your MedianFinder object will be instantiated and called as such:
- * obj := Constructor();
- * obj.AddNum(num);
- * param_2 := obj.FindMedian();
- */
-
 type hp struct{ sort.IntSlice }
 
 func (h hp) Less(i, j int) bool { return h.IntSlice[i] < h.IntSlice[j] }
@@ -39,4 +33,11 @@ func (h *hp) Pop() any {
 	v := a[len(a)-1]
 	h.IntSlice = a[:len(a)-1]
 	return v
-}
\ No newline at end of file
+}
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * obj := Constructor();
+ * obj.AddNum(num);
+ * param_2 := obj.FindMedian();
+ */

From 3d377e36d239449fa40c149d8abede7861e1095e Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:24:46 +0800
Subject: [PATCH 09/16] Update Solution.js

---
 .../Solution.js                               | 33 ++++++++++---------
 1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.js b/solution/0200-0299/0295.Find Median from Data Stream/Solution.js
index 8e67a7a2aa5e1..5e38a201dc1d8 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.js	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.js	
@@ -1,8 +1,6 @@
-/**
- * initialize your data structure here.
- */
 var MedianFinder = function () {
-    this.val = [];
+    this.minQ = new MinPriorityQueue();
+    this.maxQ = new MaxPriorityQueue();
 };
 
 /**
@@ -10,23 +8,26 @@ var MedianFinder = function () {
  * @return {void}
  */
 MedianFinder.prototype.addNum = function (num) {
-    let left = 0;
-    let right = this.val.length;
-    while (left < right) {
-        let mid = left + ~~((right - left) / 2);
-        if (num > this.val[mid]) {
-            left = mid + 1;
-        } else {
-            right = mid;
-        }
+    this.maxQ.enqueue(num);
+    this.minQ.enqueue(this.maxQ.dequeue().element);
+    if (this.minQ.size() - this.maxQ.size() > 1) {
+        this.maxQ.enqueue(this.minQ.dequeue().element);
     }
-    this.val.splice(left, 0, num);
 };
 
 /**
  * @return {number}
  */
 MedianFinder.prototype.findMedian = function () {
-    let mid = ~~(this.val.length / 2);
-    return this.val.length % 2 ? this.val[mid] : (this.val[mid - 1] + this.val[mid]) / 2;
+    if (this.minQ.size() === this.maxQ.size()) {
+        return (this.minQ.front().element + this.maxQ.front().element) / 2;
+    }
+    return this.minQ.front().element;
 };
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * var obj = new MedianFinder()
+ * obj.addNum(num)
+ * var param_2 = obj.findMedian()
+ */

From b2a524734320796d80a7cfca92c95079c5ad5013 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:25:01 +0800
Subject: [PATCH 10/16] Update Solution.ts

---
 .../Solution.ts                               | 32 +++++++------------
 1 file changed, 11 insertions(+), 21 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.ts b/solution/0200-0299/0295.Find Median from Data Stream/Solution.ts
index 8d02f1c2588a9..0df774deac49f 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.ts	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.ts	
@@ -1,32 +1,22 @@
 class MedianFinder {
-    private nums: number[];
-
-    constructor() {
-        this.nums = [];
-    }
+    #minQ = new MinPriorityQueue();
+    #maxQ = new MaxPriorityQueue();
 
     addNum(num: number): void {
-        const { nums } = this;
-        let l = 0;
-        let r = nums.length;
-        while (l < r) {
-            const mid = (l + r) >>> 1;
-            if (nums[mid] < num) {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        maxQ.enqueue(num);
+        minQ.enqueue(maxQ.dequeue().element);
+        if (minQ.size() - maxQ.size() > 1) {
+            maxQ.enqueue(minQ.dequeue().element);
         }
-        nums.splice(l, 0, num);
     }
 
     findMedian(): number {
-        const { nums } = this;
-        const n = nums.length;
-        if ((n & 1) === 1) {
-            return nums[n >> 1];
+        const [minQ, maxQ] = [this.#minQ, this.#maxQ];
+        if (minQ.size() === maxQ.size()) {
+            return (minQ.front().element + maxQ.front().element) / 2;
         }
-        return (nums[n >> 1] + nums[(n >> 1) - 1]) / 2;
+        return minQ.front().element;
     }
 }
 

From dcc257a30f8b55466204da3e4a9def4ca4a41a55 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:25:08 +0800
Subject: [PATCH 11/16] Update Solution.rs

---
 .../Solution.rs                               | 41 +++++++++----------
 1 file changed, 20 insertions(+), 21 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.rs b/solution/0200-0299/0295.Find Median from Data Stream/Solution.rs
index 52b8117baf98c..e3a7d37dfb505 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.rs	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.rs	
@@ -1,36 +1,35 @@
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
 struct MedianFinder {
-    nums: Vec<i32>,
+    minQ: BinaryHeap<Reverse<i32>>,
+    maxQ: BinaryHeap<i32>,
 }
 
-/**
- * `&self` means the method takes an immutable reference.
- * If you need a mutable reference, change it to `&mut self` instead.
- */
 impl MedianFinder {
-    /** initialize your data structure here. */
     fn new() -> Self {
-        Self { nums: Vec::new() }
+        MedianFinder {
+            minQ: BinaryHeap::new(),
+            maxQ: BinaryHeap::new(),
+        }
     }
 
     fn add_num(&mut self, num: i32) {
-        let mut l = 0;
-        let mut r = self.nums.len();
-        while l < r {
-            let mid = (l + r) >> 1;
-            if self.nums[mid] < num {
-                l = mid + 1;
-            } else {
-                r = mid;
-            }
+        self.maxQ.push(num);
+        self.minQ.push(Reverse(self.maxQ.pop().unwrap()));
+
+        if self.minQ.len() > self.maxQ.len() + 1 {
+            self.maxQ.push(self.minQ.pop().unwrap().0);
         }
-        self.nums.insert(l, num);
     }
 
     fn find_median(&self) -> f64 {
-        let n = self.nums.len();
-        if (n & 1) == 1 {
-            return f64::from(self.nums[n >> 1]);
+        if self.minQ.len() == self.maxQ.len() {
+            let min_top = self.minQ.peek().unwrap().0;
+            let max_top = *self.maxQ.peek().unwrap();
+            (min_top + max_top) as f64 / 2.0
+        } else {
+            self.minQ.peek().unwrap().0 as f64
         }
-        f64::from(self.nums[n >> 1] + self.nums[(n >> 1) - 1]) / 2.0
     }
 }

From 5458b9e1343d0c8cfe431a6f3cf5e3afb21d002e Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:25:18 +0800
Subject: [PATCH 12/16] Update Solution.cs

---
 .../Solution.cs                               | 43 +++----------------
 1 file changed, 7 insertions(+), 36 deletions(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.cs b/solution/0200-0299/0295.Find Median from Data Stream/Solution.cs
index 9ec974fe07e5f..6f5d6400527d3 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.cs	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.cs	
@@ -1,50 +1,21 @@
 public class MedianFinder {
-    private List<int> nums;
-    private int curIndex;
+    private PriorityQueue<int, int> minQ = new PriorityQueue<int, int>();
+    private PriorityQueue<int, int> maxQ = new PriorityQueue<int, int>(Comparer<int>.Create((a, b) => b.CompareTo(a)));
 
-    /** initialize your data structure here. */
     public MedianFinder() {
-        nums = new List<int>();
-    }
 
-    private int FindIndex(int val) {
-        int left = 0;
-        int right = nums.Count - 1;
-        while (left <= right) {
-            int mid = left + (right - left) / 2;
-            if (val > nums[mid]) {
-                left = mid + 1;
-            } else {
-                right = mid - 1;
-            }
-        }
-        return left;
     }
 
     public void AddNum(int num) {
-        if (nums.Count == 0) {
-            nums.Add(num);
-            curIndex = 0;
-        } else {
-            curIndex = FindIndex(num);
-            if (curIndex == nums.Count) {
-                nums.Add(num);
-            } else {
-                nums.Insert(curIndex, num);
-            }
+        maxQ.Enqueue(num, num);
+        minQ.Enqueue(maxQ.Peek(), maxQ.Dequeue());
+        if (minQ.Count > maxQ.Count + 1) {
+            maxQ.Enqueue(minQ.Peek(), minQ.Dequeue());
         }
     }
 
     public double FindMedian() {
-        if (nums.Count % 2 == 1) {
-            return (double)nums[nums.Count / 2];
-        } else {
-            if (nums.Count == 0) {
-                return 0;
-            } else {
-                return (double) (nums[nums.Count / 2 - 1] + nums[nums.Count / 2]) / 2;
-            }
-        }
+        return minQ.Count == maxQ.Count ? (minQ.Peek() + maxQ.Peek()) / 2.0 : minQ.Peek();
     }
 }
 

From 9b5a2bede9d258b60d21ee1ed033ff5e0bc327b3 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:25:31 +0800
Subject: [PATCH 13/16] Create Solution.swift

---
 .../Solution.swift                            | 111 ++++++++++++++++++
 1 file changed, 111 insertions(+)
 create mode 100644 solution/0200-0299/0295.Find Median from Data Stream/Solution.swift

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.swift b/solution/0200-0299/0295.Find Median from Data Stream/Solution.swift
new file mode 100644
index 0000000000000..bf1b16b0ac17b
--- /dev/null
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.swift	
@@ -0,0 +1,111 @@
+class MedianFinder {
+    private var minQ = Heap<Int>(sort: <)
+    private var maxQ = Heap<Int>(sort: >)
+
+    init() {
+    }
+
+    func addNum(_ num: Int) {
+        maxQ.insert(num)
+        minQ.insert(maxQ.remove()!)
+        if maxQ.count < minQ.count {
+            maxQ.insert(minQ.remove()!)
+        }
+    }
+
+    func findMedian() -> Double {
+        if maxQ.count > minQ.count {
+            return Double(maxQ.peek()!)
+        }
+        return (Double(maxQ.peek()!) + Double(minQ.peek()!)) / 2.0
+    }
+}
+
+struct Heap<T> {
+    var elements: [T]
+    let sort: (T, T) -> Bool
+
+    init(sort: @escaping (T, T) -> Bool, elements: [T] = []) {
+        self.sort = sort
+        self.elements = elements
+        if !elements.isEmpty {
+            for i in stride(from: elements.count / 2 - 1, through: 0, by: -1) {
+                siftDown(from: i)
+            }
+        }
+    }
+
+    var isEmpty: Bool {
+        return elements.isEmpty
+    }
+
+    var count: Int {
+        return elements.count
+    }
+
+    func peek() -> T? {
+        return elements.first
+    }
+
+    mutating func insert(_ value: T) {
+        elements.append(value)
+        siftUp(from: elements.count - 1)
+    }
+
+    mutating func remove() -> T? {
+        guard !elements.isEmpty else { return nil }
+        elements.swapAt(0, elements.count - 1)
+        let removedValue = elements.removeLast()
+        siftDown(from: 0)
+        return removedValue
+    }
+
+    private mutating func siftUp(from index: Int) {
+        var child = index
+        var parent = parentIndex(ofChildAt: child)
+        while child > 0 && sort(elements[child], elements[parent]) {
+            elements.swapAt(child, parent)
+            child = parent
+            parent = parentIndex(ofChildAt: child)
+        }
+    }
+
+    private mutating func siftDown(from index: Int) {
+        var parent = index
+        while true {
+            let left = leftChildIndex(ofParentAt: parent)
+            let right = rightChildIndex(ofParentAt: parent)
+            var candidate = parent
+            if left < count && sort(elements[left], elements[candidate]) {
+                candidate = left
+            }
+            if right < count && sort(elements[right], elements[candidate]) {
+                candidate = right
+            }
+            if candidate == parent {
+                return
+            }
+            elements.swapAt(parent, candidate)
+            parent = candidate
+        }
+    }
+
+    private func parentIndex(ofChildAt index: Int) -> Int {
+        return (index - 1) / 2
+    }
+
+    private func leftChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 1
+    }
+
+    private func rightChildIndex(ofParentAt index: Int) -> Int {
+        return 2 * index + 2
+    }
+}
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * let obj = MedianFinder()
+ * obj.addNum(num)
+ * let ret_2: Double = obj.findMedian()
+ */

From 84274e88bd86e98febf7bcd4719c3bd9d95eb16b Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:27:16 +0800
Subject: [PATCH 14/16] Update Solution.java

---
 .../0200-0299/0295.Find Median from Data Stream/Solution.java    | 1 -
 1 file changed, 1 deletion(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/Solution.java b/solution/0200-0299/0295.Find Median from Data Stream/Solution.java
index c0b04faf7af10..4fedda85b0558 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/Solution.java	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/Solution.java	
@@ -3,7 +3,6 @@ class MedianFinder {
     private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
     public MedianFinder() {
-
     }
 
     public void addNum(int num) {

From 05caeb00e8d52ce4a8df033bf6136607a6414935 Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:27:32 +0800
Subject: [PATCH 15/16] Update README.md

---
 solution/0200-0299/0295.Find Median from Data Stream/README.md | 1 -
 1 file changed, 1 deletion(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README.md b/solution/0200-0299/0295.Find Median from Data Stream/README.md
index d9c15caab2ad3..e2121ad724561 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README.md	
@@ -118,7 +118,6 @@ class MedianFinder {
     private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
     public MedianFinder() {
-
     }
 
     public void addNum(int num) {

From f94c8cb17bf6f113a8d52c34c0c32e3837e57bee Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 28 Jun 2024 08:27:48 +0800
Subject: [PATCH 16/16] Update README_EN.md

---
 .../0200-0299/0295.Find Median from Data Stream/README_EN.md     | 1 -
 1 file changed, 1 deletion(-)

diff --git a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md
index 957d11c6a5a67..c2787a62043d6 100644
--- a/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
+++ b/solution/0200-0299/0295.Find Median from Data Stream/README_EN.md	
@@ -123,7 +123,6 @@ class MedianFinder {
     private PriorityQueue<Integer> maxQ = new PriorityQueue<>(Collections.reverseOrder());
 
     public MedianFinder() {
-
     }
 
     public void addNum(int num) {