Palindrome Number

Determine whether an integer is a palindrome. Do this without extra space.

方法：数字前后位分别提取并进行判断是否相等。

class Solution { public: bool isPalindrome(int x) { if(x<0) return false; int y = x; int len = 1; while(y/10!=0){ len++; y/=10; } bool isValid ; int left = len-1 ,right = 1; while(left >= right){ int big = x /static_cast<int>(pow(10,left)) % 10; int small = x % static_cast<int>((pow(10,right)))/pow(10,right-1); if(big != small) return false; --left; ++right; } return true; } };