From 59eff2e01b24169c168e96e685c0fd00c3be8ab9 Mon Sep 17 00:00:00 2001
From: Jerry-306 <82520819+Jerry-306@users.noreply.github.com>
Date: Sat, 25 Sep 2021 09:27:29 +0800
Subject: [PATCH] =?UTF-8?q?=E8=A1=A5=E5=85=85=200202=20=E5=BF=AB=E4=B9=90?=
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 =?UTF-8?q?t()=20=E7=9A=84=E8=A7=A3=E6=B3=95?=
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---
 problems/0202.快乐数.md | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/problems/0202.快乐数.md b/problems/0202.快乐数.md
index 02db507a..43c9d753 100644
--- a/problems/0202.快乐数.md
+++ b/problems/0202.快乐数.md
@@ -191,6 +191,30 @@ var isHappy = function(n) {
     }
     return b === 1 || getN(b) === 1 ;
 };
+
+// 方法三：使用Set()更简洁
+/**
+ * @param {number} n
+ * @return {boolean}
+ */
+
+var getSum = function (n) {
+    let sum = 0;
+    while (n) {
+        sum += (n % 10) ** 2;
+        n =  Math.floor(n/10);
+    }
+    return sum;
+}
+var isHappy = function(n) {
+    let set = new Set();   // Set() 里的数是惟一的
+    // 如果在循环中某个值重复出现，说明此时陷入死循环，也就说明这个值不是快乐数
+    while (n !== 1 && !set.has(n)) {
+        set.add(n);
+        n = getSum(n);
+    }
+    return n === 1;
+};
 ```
 
 Swift：