From f172c95e882e4eb8cc13636469588f81c5695bc4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E6=9E=81=E5=AE=A2=E5=AD=A6=E4=BC=9F?= <qxuwei@yeah.net>
Date: Tue, 31 Aug 2021 14:36:45 +0800
Subject: [PATCH] =?UTF-8?q?=E6=B7=BB=E5=8A=A0=20=E7=AC=AC202=E9=A2=98.=20?=
 =?UTF-8?q?=E5=BF=AB=E4=B9=90=E6=95=B0=20Swift=E7=89=88=E6=9C=AC?=
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---
 problems/0202.快乐数.md | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

diff --git a/problems/0202.快乐数.md b/problems/0202.快乐数.md
index b9386a68..e6365c71 100644
--- a/problems/0202.快乐数.md
+++ b/problems/0202.快乐数.md
@@ -191,7 +191,37 @@ var isHappy = function(n) {
 };
 ```
 
-
+Swift：
+```swift
+// number 每个位置上的数字的平方和
+func getSum(_ number: Int) -> Int {
+    var sum = 0
+    var num = number
+    while num > 0 {
+        let temp = num % 10
+        sum += (temp * temp)
+        num /= 10
+    }
+    return sum
+}
+func isHappy(_ n: Int) -> Bool {
+    var set = Set<Int>()
+    var num = n
+    while true {
+        let sum = self.getSum(num)
+        if sum == 1 {
+            return true
+        }
+        // 如果这个sum曾经出现过，说明已经陷入了无限循环了
+        if set.contains(sum) {
+            return false
+        } else {
+            set.insert(sum)
+        }
+        num = sum
+    }
+}
+```
 
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 * 作者微信：[程序员Carl](https://mp.weixin.qq.com/s/b66DFkOp8OOxdZC_xLZxfw)