add 300, 367, 383, 567, 1952, 2200, 2367, 2706 update 1512 at swift

rozinko · rozinko · commit b383b21c4884 · 2025-06-24T13:47:28.000+03:00
diff --git a/swift/0300-longest-increasing-subsequence.swift b/swift/0300-longest-increasing-subsequence.swift
@@ -0,0 +1,20 @@
+/**
+ * 300. Longest Increasing Subsequence
+ * https://leetcode.com/problems/longest-increasing-subsequence/
+ **/
+
+class Solution {
+    func lengthOfLIS(_ nums: [Int]) -> Int {
+        var dp: [Int] = Array(repeating: 1, count: nums.count)
+
+        for i in 0 ..< nums.count {
+            for j in 0 ..< i {
+                if nums[i] > nums[j] {
+                    dp[i] = max(dp[i], dp[j] + 1)
+                }
+            }
+        }
+
+        return dp.max()!
+    }
+}
diff --git a/swift/0367-valid-perfect-square.swift b/swift/0367-valid-perfect-square.swift
@@ -0,0 +1,13 @@
+/**
+ * 367. Valid Perfect Square
+ * https://leetcode.com/problems/valid-perfect-square/
+ **/
+
+class Solution {
+    func isPerfectSquare(_ num: Int) -> Bool {
+        for i in 1 ... num where i * i >= num {
+            return i * i == num
+        }
+        return false
+    }
+}
diff --git a/swift/0383-ransom-note.swift b/swift/0383-ransom-note.swift
@@ -0,0 +1,24 @@
+/**
+ * 383. Ransom Note
+ * https://leetcode.com/problems/ransom-note/
+ **/
+
+class Solution {
+    func canConstruct(_ ransomNote: String, _ magazine: String) -> Bool {
+        var dict: [Character: (note: Int, magazine: Int)] = [:]
+
+        for ch in ransomNote {
+            dict[ch, default: (0, 0)].note += 1
+        }
+
+        for ch in magazine {
+            dict[ch, default: (0, 0)].magazine += 1
+        }
+
+        for (note, magaz) in dict.values where note > magaz {
+            return false
+        }
+
+        return true
+    }
+}
diff --git a/swift/0567-permutation-in-string.swift b/swift/0567-permutation-in-string.swift
@@ -0,0 +1,36 @@
+/**
+ * 567. Permutation in String
+ * https://leetcode.com/problems/permutation-in-string/
+ **/
+
+class Solution {
+    func checkInclusion(_ s1: String, _ s2: String) -> Bool {
+        guard s1.count <= s2.count else { return false }
+
+        let s2arr = Array(s2)
+        let s1count = s1.count, s2count = s2.count
+        var dict: [Character: Int] = [:]
+
+        for ch in s1 {
+            dict[ch, default: 0] += 1
+        }
+
+        var l = 0, r = -1
+        while l + r + 1 < s1count {
+            r += 1
+            dict[s2arr[r], default: 0] -= 1
+            if dict[s2arr[r]] == 0 { dict[s2arr[r]] = nil }
+        }
+
+        while !dict.isEmpty && r < s2count - 1 {
+            r += 1
+            dict[s2arr[r], default: 0] -= 1
+            if dict[s2arr[r]] == 0 { dict[s2arr[r]] = nil }
+            dict[s2arr[l], default: 0] += 1
+            if dict[s2arr[l]] == 0 { dict[s2arr[l]] = nil }
+            l += 1
+        }
+
+        return dict.isEmpty
+    }
+}
diff --git a/swift/1512-number-of-good-pairs.swift b/swift/1512-number-of-good-pairs.swift
@@ -13,4 +13,24 @@ class Solution {
 
         return prev.filter{$0.value > 1}.map{$0.value * ($0.value-1) / 2}.reduce(0, +)
     }
+}
+
+class Solution2 {
+    func numIdenticalPairs(_ nums: [Int]) -> Int {
+        var dict: [Int: Int] = [:], ans = 0
+
+        for (i, v) in nums.enumerated() {
+            dict[v, default: 0] += 1
+        }
+
+        for pairCount in dict.values where pairCount > 1 {
+            var temp = pairCount
+            while temp > 1 {
+                ans += temp - 1
+                temp -= 1
+            }
+        }
+
+        return ans
+    }
 }
diff --git a/swift/1952-three-divisors.swift b/swift/1952-three-divisors.swift
@@ -0,0 +1,17 @@
+/**
+ * 1952. Three Divisors
+ * https://leetcode.com/problems/three-divisors/
+ **/
+
+class Solution {
+    func isThree(_ n: Int) -> Bool {
+        var divisors = 0
+
+        for i in 1 ... n where n % i == 0 {
+            divisors += 1
+            if divisors > 3 { return false }
+        }
+
+        return divisors == 3
+    }
+}
diff --git a/swift/2200-find-all-k-distant-indices-in-an-array.swift b/swift/2200-find-all-k-distant-indices-in-an-array.swift
@@ -0,0 +1,18 @@
+/**
+ * 2200. Find All K-Distant Indices in an Array
+ * https://leetcode.com/problems/find-all-k-distant-indices-in-an-array/
+ **/
+
+class Solution {
+    func findKDistantIndices(_ nums: [Int], _ key: Int, _ k: Int) -> [Int] {
+        var ans: [Int] = []
+        var from = 0
+        for i in 0 ..< nums.count where nums[i] == key {
+            for j in max(from, i - k) ... i + k where j < nums.count {
+                ans.append(j)
+            }
+            from = i + k + 1
+        }
+        return ans
+    }
+}
diff --git a/swift/2367-number-of-arithmetic-triplets.swift b/swift/2367-number-of-arithmetic-triplets.swift
@@ -0,0 +1,18 @@
+/**
+ * 2367. Number of Arithmetic Triplets
+ * https://leetcode.com/problems/number-of-arithmetic-triplets/
+ **/
+
+class Solution {
+    func arithmeticTriplets(_ nums: [Int], _ diff: Int) -> Int {
+        var ans = 0
+        for (i, iv) in nums.enumerated() {
+            for (j, jv) in nums.enumerated() where j > i && jv - iv == diff {
+                for (k, kv) in nums.enumerated() where k > j && kv - jv == diff {
+                    ans += 1
+                }
+            }
+        }
+        return ans
+    }
+}
diff --git a/swift/2706-buy-two-chocolates.swift b/swift/2706-buy-two-chocolates.swift
@@ -0,0 +1,11 @@
+/**
+ * 2706. Buy Two Chocolates
+ * https://leetcode.com/problems/buy-two-chocolates/
+ **/
+
+class Solution {
+    func buyChoco(_ prices: [Int], _ money: Int) -> Int {
+        let prices = prices.sorted()
+        return prices[0] + prices[1] <= money ? money - prices[0] - prices[1] : money
+    }
+}
