From f59904e5a9acde2bc916700f21eb39df2241e844 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E5=94=90=E6=A0=91=E6=A3=AE?= <14021051@buaa.edu.cn>
Date: Wed, 26 Sep 2018 23:28:35 +0800
Subject: [PATCH] Create 9. Palindrome Number.md

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+# [9. Palindrome Number](https://leetcode.com/problems/palindrome-number/description/)
+# 思路
+判断一个int型数是否为回文数。   
+首先小于0肯定不是可以直接返回false；  
+对于一般的int型数，可以先将其转换成字符串，这样判断是否回文就快多了。   
+# C++
+```
+class Solution {
+public:
+    bool isPalindrome(int x) {
+        if(x < 0) return false;
+        if(x < 10) return true;
+        if(x % 10 == 0) return false;
+        // std::string s = std::to_string(x); // 注意学习这种将int型转字符串的简单方法
+        auto s = std::to_string(x);
+        int low = 0, high = s.size() - 1;
+        while(low < high){
+            if(s[low++] != s[high--]) return false;
+        }
+        return true;
+    }
+};
+```