From c82bf133d4d6f95212ab42bfbcdb6af68927d9df Mon Sep 17 00:00:00 2001
From: bqlin <bqlins@163.com>
Date: Sun, 12 Dec 2021 12:54:37 +0800
Subject: [PATCH] =?UTF-8?q?0131.=E5=88=86=E5=89=B2=E5=9B=9E=E6=96=87?=
 =?UTF-8?q?=E4=B8=B2=EF=BC=9A=E4=BC=98=E5=8C=96=E6=8E=92=E7=89=88=EF=BC=8C?=
 =?UTF-8?q?=E8=A1=A5=E5=85=85Swift=E7=89=88=E6=9C=AC?=
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---
 problems/0131.分割回文串.md | 46 +++++++++++++++++++++++++++++++-
 1 file changed, 45 insertions(+), 1 deletion(-)

diff --git a/problems/0131.分割回文串.md b/problems/0131.分割回文串.md
index 075734ea..47734f6c 100644
--- a/problems/0131.分割回文串.md
+++ b/problems/0131.分割回文串.md
@@ -450,7 +450,8 @@ var partition = function(s) {
 };
 ```
 
-##C
+## C
+
 ```c
 char** path;
 int pathTop;
@@ -546,5 +547,48 @@ char*** partition(char* s, int* returnSize, int** returnColumnSizes){
 }
 ```
 
+## Swift
+
+```swift
+func partition(_ s: String) -> [[String]] {
+    // 把字符串转为字符数组以便于通过索引访问和取子串
+    let s = Array(s)
+    // 使用双指针法判断子串是否回文
+    func isPalindrome(start: Int, end: Int) -> Bool {
+        var start = start, end = end
+        while start < end {
+            if s[start] != s[end] { return false }
+            start += 1
+            end -= 1
+        }
+        return true
+    }
+
+    var result = [[String]]()
+    var path = [String]() // 切割方案
+    func backtracking(startIndex: Int) {
+        // 终止条件，收集结果
+        guard startIndex < s.count else {
+            result.append(path)
+            return
+        }
+
+        for i in startIndex ..< s.count {
+            // 回文则收集，否则跳过
+            if isPalindrome(start: startIndex, end: i) {
+                let substring = String(s[startIndex ... i])
+                path.append(substring)
+            } else {
+                continue
+            }
+            backtracking(startIndex: i + 1) // 寻找下一个起始位置的子串
+            if !path.isEmpty { path.removeLast() } // 回溯
+        }
+    }
+    backtracking(startIndex: 0)
+    return result
+}
+```
+
 -----------------------
 <div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>