From 1a15ed08a5f7149acf515fd3f266cb4a756508c2 Mon Sep 17 00:00:00 2001
From: bqlin <bqlins@163.com>
Date: Sat, 11 Dec 2021 18:23:11 +0800
Subject: [PATCH] =?UTF-8?q?0077.=E7=BB=84=E5=90=88=E4=BC=98=E5=8C=96?=
 =?UTF-8?q?=EF=BC=9A=E8=A1=A5=E5=85=85Swift=E7=89=88=E6=9C=AC?=
MIME-Version: 1.0
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---
 problems/0077.组合优化.md | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/problems/0077.组合优化.md b/problems/0077.组合优化.md
index 1d725bc5..d7f7bc38 100644
--- a/problems/0077.组合优化.md
+++ b/problems/0077.组合优化.md
@@ -294,5 +294,35 @@ int** combine(int n, int k, int* returnSize, int** returnColumnSizes){
 }
 ```
 
+Swift：
+
+```swift
+func combine(_ n: Int, _ k: Int) -> [[Int]] {
+    var path = [Int]()
+    var result = [[Int]]()
+    func backtracking(_ n: Int, _ k: Int, _ startIndex: Int) {
+        // 结束条件，并收集结果
+        if path.count == k {
+            result.append(path)
+            return
+        }
+
+        // 单层逻辑
+        // let end = n
+        // 剪枝优化
+        let end = n - (k - path.count) + 1
+        guard startIndex <= end else { return }
+        for i in startIndex ... end {
+            path.append(i) // 处理结点
+            backtracking(n, k, i + 1) // 递归
+            path.removeLast() // 回溯
+        }
+    }
+
+    backtracking(n, k, 1)
+    return result
+}
+```
+
 -----------------------
 <div align="center"><img src=https://code-thinking.cdn.bcebos.com/pics/01二维码一.jpg width=500> </img></div>