doocs · acbin · Mar 13, 2024 · Mar 13, 2024
diff --git a/solution/3000-3099/3063.Linked List Frequency/README.md b/solution/3000-3099/3063.Linked List Frequency/README.md
@@ -8,7 +8,7 @@
 
 <!-- 这里写题目描述 -->
 
-<p>给定包含 <code>k</code> 个&nbsp;<strong>不同&nbsp;</strong>元素的链表的&nbsp;<code>head</code>&nbsp;节点，返回包含给定链表中每个 <strong>不同元素</strong> 以 <strong>任何顺序</strong> 出现的 <span data-keyword="frequency-linkedlist">频率</span> 的长度为&nbsp;<code>k</code>&nbsp;的链表的头节点。</p>
+<p>给定包含 <code>k</code> 个&nbsp;<strong>不同&nbsp;</strong>元素的链表的&nbsp;<code>head</code>&nbsp;节点，创建一个长度为&nbsp;<code>k</code>&nbsp;的链表，包含给定链表中每个 <strong>不同元素</strong> 以 <strong>任何顺序</strong> 出现的 <span data-keyword="frequency-linkedlist">频率</span>&nbsp;。返回这个链表的头节点。</p>
 
 <p>&nbsp;</p>
 

diff --git a/solution/3000-3099/3073.Maximum Increasing Triplet Value/README.md b/solution/3000-3099/3073.Maximum Increasing Triplet Value/README.md
@@ -2,7 +2,7 @@
 
 [English Version](/solution/3000-3099/3073.Maximum%20Increasing%20Triplet%20Value/README_EN.md)
 
-<!-- tags: -->
+<!-- tags:数组,有序集合 -->
 
 ## 题目描述
 

diff --git a/solution/3000-3099/3073.Maximum Increasing Triplet Value/README_EN.md b/solution/3000-3099/3073.Maximum Increasing Triplet Value/README_EN.md
@@ -2,7 +2,7 @@
 
 [中文文档](/solution/3000-3099/3073.Maximum%20Increasing%20Triplet%20Value/README.md)
 
-<!-- tags: -->
+<!-- tags:Array,Ordered Set -->
 
 ## Description
 

diff --git a/solution/3000-3099/3074.Apple Redistribution into Boxes/README.md b/solution/3000-3099/3074.Apple Redistribution into Boxes/README.md
@@ -2,7 +2,7 @@
 
 [English Version](/solution/3000-3099/3074.Apple%20Redistribution%20into%20Boxes/README_EN.md)
 
-<!-- tags: -->
+<!-- tags:贪心,数组,排序 -->
 
 ## 题目描述
 

diff --git a/solution/3000-3099/3074.Apple Redistribution into Boxes/README_EN.md b/solution/3000-3099/3074.Apple Redistribution into Boxes/README_EN.md
@@ -2,7 +2,7 @@
 
 [中文文档](/solution/3000-3099/3074.Apple%20Redistribution%20into%20Boxes/README.md)
 
-<!-- tags: -->
+<!-- tags:Greedy,Array,Sorting -->
 
 ## Description
 

diff --git a/solution/3000-3099/3075.Maximize Happiness of Selected Children/README.md b/solution/3000-3099/3075.Maximize Happiness of Selected Children/README.md
@@ -2,7 +2,7 @@
 
 [English Version](/solution/3000-3099/3075.Maximize%20Happiness%20of%20Selected%20Children/README_EN.md)
 
-<!-- tags: -->
+<!-- tags:贪心,数组,排序 -->
 
 ## 题目描述
 
@@ -121,6 +121,18 @@ func maximumHappinessSum(happiness []int, k int) (ans int64) {
 }
 ```
 
+```ts
+function maximumHappinessSum(happiness: number[], k: number): number {
+    happiness.sort((a, b) => b - a);
+    let ans = 0;
+    for (let i = 0; i < k; ++i) {
+        const x = happiness[i] - i;
+        ans += Math.max(x, 0);
+    }
+    return ans;
+}
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/solution/3000-3099/3075.Maximize Happiness of Selected Children/README_EN.md b/solution/3000-3099/3075.Maximize Happiness of Selected Children/README_EN.md
@@ -2,7 +2,7 @@
 
 [中文文档](/solution/3000-3099/3075.Maximize%20Happiness%20of%20Selected%20Children/README.md)
 
-<!-- tags: -->
+<!-- tags:Greedy,Array,Sorting -->
 
 ## Description
 

diff --git a/solution/3000-3099/3076.Shortest Uncommon Substring in an Array/README.md b/solution/3000-3099/3076.Shortest Uncommon Substring in an Array/README.md
@@ -2,7 +2,7 @@
 
 [English Version](/solution/3000-3099/3076.Shortest%20Uncommon%20Substring%20in%20an%20Array/README_EN.md)
 
-<!-- tags: -->
+<!-- tags:字典树,数组,哈希表,字符串 -->
 
 ## 题目描述
 

diff --git a/solution/3000-3099/3076.Shortest Uncommon Substring in an Array/README_EN.md b/solution/3000-3099/3076.Shortest Uncommon Substring in an Array/README_EN.md
@@ -2,7 +2,7 @@
 
 [中文文档](/solution/3000-3099/3076.Shortest%20Uncommon%20Substring%20in%20an%20Array/README.md)
 
-<!-- tags: -->
+<!-- tags:Trie,Array,Hash Table,String -->
 
 ## Description
 

diff --git a/solution/3000-3099/3077.Maximum Strength of K Disjoint Subarrays/README.md b/solution/3000-3099/3077.Maximum Strength of K Disjoint Subarrays/README.md
@@ -2,7 +2,7 @@
 
 [English Version](/solution/3000-3099/3077.Maximum%20Strength%20of%20K%20Disjoint%20Subarrays/README_EN.md)
 
-<!-- tags: -->
+<!-- tags:数组,动态规划,前缀和 -->
 
 ## 题目描述
 
@@ -58,24 +58,150 @@
 
 ## 解法
 
-### 方法一
+### 方法一：动态规划
+
+对于第 $i$ 个数 $nums[i - 1]$，如果它被选择，且位于第 $j$ 个子数组，那么它对答案的贡献是 $nums[i - 1] \times (k - j + 1) \times (-1)^{j+1}$，我们不妨将 $(-1)^{j+1}$ 记为 $sign$，那么它对答案的贡献是 $sign \times nums[i - 1] \times (k - j + 1)$。
+
+我们定义 $f[i][j][0]$ 表示从前 $i 个数中选择 $j$ 个子数组，且第 $i$ 个数不被选的最大能量值，定义 $f[i][j][1]$ 表示从前 $i$ 个数中选择 $j$ 个子数组，且第 $i$ 个数被选的最大能量值。初始时 $f[0][0][1] = 0$，其余的值都是 $-\infty$。
+
+当 $i > 0$ 时，我们考虑 $f[i][j]$ 如何进行状态转移。
+
+如果第 $i$ 个数不被选，那么第 $i-1$ 个数既可以被选，也可以不被选，所以 $f[i][j][0] = \max(f[i-1][j][0], f[i-1][j][1])$。
+
+如果第 $i$ 个数被选，此时如果第 $i-1$ 个数与第 $i$ 个数位于同一个子数组中，那么 $f[i][j][1] = \max(f[i][j][1], f[i-1][j][1] + sign \times nums[i-1] \times (k - j + 1))$，否则 $f[i][j][1] = \max(f[i][j][1], \max(f[i-1][j-1][0], f[i-1][j-1][1]) + sign \times nums[i-1] \times (k - j + 1))$。我们取这两种情况的最大值作为 $f[i][j][1]$。
+
+最终答案是 $\max(f[n][k][0], f[n][k][1])$。
+
+时间复杂度 $O(n \times k)$，空间复杂度 $O(n \times k)$。其中 $n$ 是数组 $nums$ 的长度。
 
 <!-- tabs:start -->
 
 ```python
-
+class Solution:
+    def maximumStrength(self, nums: List[int], k: int) -> int:
+        n = len(nums)
+        f = [[[-inf, -inf] for _ in range(k + 1)] for _ in range(n + 1)]
+        f[0][0][0] = 0
+        for i, x in enumerate(nums, 1):
+            for j in range(k + 1):
+                sign = 1 if j & 1 else -1
+                f[i][j][0] = max(f[i - 1][j][0], f[i - 1][j][1])
+                f[i][j][1] = max(f[i][j][1], f[i - 1][j][1] + sign * x * (k - j + 1))
+                if j:
+                    f[i][j][1] = max(
+                        f[i][j][1], max(f[i - 1][j - 1]) + sign * x * (k - j + 1)
+                    )
+        return max(f[n][k])
 ```
 
 ```java
-
+class Solution {
+    public long maximumStrength(int[] nums, int k) {
+        int n = nums.length;
+        long[][][] f = new long[n + 1][k + 1][2];
+        for (int i = 0; i <= n; i++) {
+            for (int j = 0; j <= k; j++) {
+                Arrays.fill(f[i][j], Long.MIN_VALUE / 2);
+            }
+        }
+        f[0][0][0] = 0;
+        for (int i = 1; i <= n; i++) {
+            int x = nums[i - 1];
+            for (int j = 0; j <= k; j++) {
+                long sign = (j & 1) == 1 ? 1 : -1;
+                long val = sign * x * (k - j + 1);
+                f[i][j][0] = Math.max(f[i - 1][j][0], f[i - 1][j][1]);
+                f[i][j][1] = Math.max(f[i][j][1], f[i - 1][j][1] + val);
+                if (j > 0) {
+                    long t = Math.max(f[i - 1][j - 1][0], f[i - 1][j - 1][1]) + val;
+                    f[i][j][1] = Math.max(f[i][j][1], t);
+                }
+            }
+        }
+        return Math.max(f[n][k][0], f[n][k][1]);
+    }
+}
 ```
 
 ```cpp
-
+class Solution {
+public:
+    long long maximumStrength(vector<int>& nums, int k) {
+        int n = nums.size();
+        long long f[n + 1][k + 1][2];
+        memset(f, -0x3f3f3f3f3f3f3f3f, sizeof(f));
+        f[0][0][0] = 0;
+        for (int i = 1; i <= n; i++) {
+            int x = nums[i - 1];
+            for (int j = 0; j <= k; j++) {
+                long long sign = (j & 1) == 1 ? 1 : -1;
+                long long val = sign * x * (k - j + 1);
+                f[i][j][0] = max(f[i - 1][j][0], f[i - 1][j][1]);
+                f[i][j][1] = max(f[i][j][1], f[i - 1][j][1] + val);
+                if (j > 0) {
+                    long long t = max(f[i - 1][j - 1][0], f[i - 1][j - 1][1]) + val;
+                    f[i][j][1] = max(f[i][j][1], t);
+                }
+            }
+        }
+        return max(f[n][k][0], f[n][k][1]);
+    }
+};
 ```
 
 ```go
+func maximumStrength(nums []int, k int) int64 {
+	n := len(nums)
+	f := make([][][]int64, n+1)
+	const inf int64 = math.MinInt64 / 2
+	for i := range f {
+		f[i] = make([][]int64, k+1)
+		for j := range f[i] {
+			f[i][j] = []int64{inf, inf}
+		}
+	}
+	f[0][0][0] = 0
+	for i := 1; i <= n; i++ {
+		x := nums[i-1]
+		for j := 0; j <= k; j++ {
+			sign := int64(-1)
+			if j&1 == 1 {
+				sign = 1
+			}
+			val := sign * int64(x) * int64(k-j+1)
+			f[i][j][0] = max(f[i-1][j][0], f[i-1][j][1])
+			f[i][j][1] = max(f[i][j][1], f[i-1][j][1]+val)
+			if j > 0 {
+				t := max(f[i-1][j-1][0], f[i-1][j-1][1]) + val
+				f[i][j][1] = max(f[i][j][1], t)
+			}
+		}
+	}
+	return max(f[n][k][0], f[n][k][1])
+}
+```
 
+```ts
+function maximumStrength(nums: number[], k: number): number {
+    const n: number = nums.length;
+    const f: number[][][] = Array.from({ length: n + 1 }, () =>
+        Array.from({ length: k + 1 }, () => [-Infinity, -Infinity]),
+    );
+    f[0][0][0] = 0;
+    for (let i = 1; i <= n; i++) {
+        const x: number = nums[i - 1];
+        for (let j = 0; j <= k; j++) {
+            const sign: number = (j & 1) === 1 ? 1 : -1;
+            const val: number = sign * x * (k - j + 1);
+            f[i][j][0] = Math.max(f[i - 1][j][0], f[i - 1][j][1]);
+            f[i][j][1] = Math.max(f[i][j][1], f[i - 1][j][1] + val);
+            if (j > 0) {
+                f[i][j][1] = Math.max(f[i][j][1], Math.max(...f[i - 1][j - 1]) + val);
+            }
+        }
+    }
+    return Math.max(...f[n][k]);
+}
 ```
 
 <!-- tabs:end -->