Merge branch 'main' into patch-5

Author: K11E3R

lcof2/剑指 Offer II 069. 山峰数组的顶部/README.md

@@ -182,6 +182,26 @@ var peakIndexInMountainArray = function (arr) {
 };
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func peakIndexInMountainArray(_ arr: [Int]) -> Int {
+        var left = 1
+        var right = arr.count - 2
+        while left < right {
+            let mid = (left + right) / 2
+            if arr[mid] > arr[mid + 1] {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        return left
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 069. 山峰数组的顶部/Solution.swift

@@ -0,0 +1,16 @@
+class Solution {
+    func peakIndexInMountainArray(_ arr: [Int]) -> Int {
+        var left = 1
+        var right = arr.count - 2
+        while left < right {
+            let mid = (left + right) / 2
+            if arr[mid] > arr[mid + 1] {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        return left
+    }
+}
+

lcof2/剑指 Offer II 070. 排序数组中只出现一次的数字/README.md

@@ -151,6 +151,28 @@ function singleNonDuplicate(nums: number[]): number {
 }
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    func singleNonDuplicate(_ nums: [Int]) -> Int {
+        var left = 0
+        var right = nums.count - 1
+        
+        while left < right {
+            let mid = (left + right) / 2
+            if nums[mid] != nums[mid ^ 1] {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        
+        return nums[left]
+    }
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 070. 排序数组中只出现一次的数字/Solution.swift

@@ -0,0 +1,17 @@
+class Solution {
+    func singleNonDuplicate(_ nums: [Int]) -> Int {
+        var left = 0
+        var right = nums.count - 1
+        
+        while left < right {
+            let mid = (left + right) / 2
+            if nums[mid] != nums[mid ^ 1] {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        
+        return nums[left]
+    }
+}

lcof2/剑指 Offer II 071. 按权重生成随机数/README.md

@@ -222,6 +222,44 @@ func (this *Solution) PickIndex() int {
  */
 ```
 
+#### Swift
+
+```swift
+class Solution {
+    private var presum: [Int]
+
+    init(_ w: [Int]) {
+        let n = w.count
+        presum = [Int](repeating: 0, count: n + 1)
+        for i in 0..<n {
+            presum[i + 1] = presum[i] + w[i]
+        }
+    }
+
+    func pickIndex() -> Int {
+        let n = presum.count
+        let x = Int.random(in: 1...presum[n - 1])
+        var left = 0
+        var right = n - 2
+        while left < right {
+            let mid = (left + right) >> 1
+            if presum[mid + 1] >= x {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        return left
+    }
+}
+/**
+ * Your Solution object will be instantiated and called as such:
+ * let w = [1]
+ * let solution = Solution(w)
+ * solution.pickIndex()
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

lcof2/剑指 Offer II 071. 按权重生成随机数/Solution.swift

@@ -0,0 +1,33 @@
+class Solution {
+    private var presum: [Int]
+
+    init(_ w: [Int]) {
+        let n = w.count
+        presum = [Int](repeating: 0, count: n + 1)
+        for i in 0..<n {
+            presum[i + 1] = presum[i] + w[i]
+        }
+    }
+
+    func pickIndex() -> Int {
+        let n = presum.count
+        let x = Int.random(in: 1...presum[n - 1])
+        var left = 0
+        var right = n - 2
+        while left < right {
+            let mid = (left + right) >> 1
+            if presum[mid + 1] >= x {
+                right = mid
+            } else {
+                left = mid + 1
+            }
+        }
+        return left
+    }
+}
+/**
+ * Your Solution object will be instantiated and called as such:
+ * let w = [1]
+ * let solution = Solution(w)
+ * solution.pickIndex()
+ */

solution/0000-0099/0017.Letter Combinations of a Phone Number/README.md

@@ -165,13 +165,13 @@ func letterCombinations(digits string) []string {
 
 ```ts
 function letterCombinations(digits: string): string[] {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans: string[] = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t: string[] = [];
         for (const a of ans) {
             for (const b of s) {
@@ -218,13 +218,13 @@ impl Solution {
  * @return {string[]}
  */
 var letterCombinations = function (digits) {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t = [];
         for (const a of ans) {
             for (const b of s) {
@@ -392,7 +392,7 @@ func letterCombinations(digits string) (ans []string) {
 
 ```ts
 function letterCombinations(digits: string): string[] {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans: string[] = [];
@@ -403,7 +403,7 @@ function letterCombinations(digits: string): string[] {
             ans.push(t.join(''));
             return;
         }
-        const s = d[parseInt(digits[i]) - 2];
+        const s = d[+digits[i] - 2];
         for (const c of s) {
             t.push(c);
             dfs(i + 1);
@@ -453,7 +453,7 @@ impl Solution {
  * @return {string[]}
  */
 var letterCombinations = function (digits) {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans = [];
@@ -464,7 +464,7 @@ var letterCombinations = function (digits) {
             ans.push(t.join(''));
             return;
         }
-        const s = d[parseInt(digits[i]) - 2];
+        const s = d[+digits[i] - 2];
         for (const c of s) {
             t.push(c);
             dfs(i + 1);

solution/0000-0099/0017.Letter Combinations of a Phone Number/README_EN.md

@@ -161,13 +161,13 @@ func letterCombinations(digits string) []string {
 
 ```ts
 function letterCombinations(digits: string): string[] {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans: string[] = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t: string[] = [];
         for (const a of ans) {
             for (const b of s) {
@@ -214,13 +214,13 @@ impl Solution {
  * @return {string[]}
  */
 var letterCombinations = function (digits) {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t = [];
         for (const a of ans) {
             for (const b of s) {
@@ -388,7 +388,7 @@ func letterCombinations(digits string) (ans []string) {
 
 ```ts
 function letterCombinations(digits: string): string[] {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans: string[] = [];
@@ -399,7 +399,7 @@ function letterCombinations(digits: string): string[] {
             ans.push(t.join(''));
             return;
         }
-        const s = d[parseInt(digits[i]) - 2];
+        const s = d[+digits[i] - 2];
         for (const c of s) {
             t.push(c);
             dfs(i + 1);
@@ -449,7 +449,7 @@ impl Solution {
  * @return {string[]}
  */
 var letterCombinations = function (digits) {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans = [];
@@ -460,7 +460,7 @@ var letterCombinations = function (digits) {
             ans.push(t.join(''));
             return;
         }
-        const s = d[parseInt(digits[i]) - 2];
+        const s = d[+digits[i] - 2];
         for (const c of s) {
             t.push(c);
             dfs(i + 1);

solution/0000-0099/0017.Letter Combinations of a Phone Number/Solution.js

@@ -3,13 +3,13 @@
  * @return {string[]}
  */
 var letterCombinations = function (digits) {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t = [];
         for (const a of ans) {
             for (const b of s) {

solution/0000-0099/0017.Letter Combinations of a Phone Number/Solution.ts

@@ -1,11 +1,11 @@
 function letterCombinations(digits: string): string[] {
-    if (digits.length == 0) {
+    if (digits.length === 0) {
         return [];
     }
     const ans: string[] = [''];
     const d = ['abc', 'def', 'ghi', 'jkl', 'mno', 'pqrs', 'tuv', 'wxyz'];
     for (const i of digits) {
-        const s = d[parseInt(i) - 2];
+        const s = d[+i - 2];
         const t: string[] = [];
         for (const a of ans) {
             for (const b of s) {