Leetcode Oj Reverse Integer

Reverse digits of an integer.

Example1: x = 123, return 321
Example2: x = -123, return -321

Level : easy

class Solution {public:    int reverse(int x) {        int sign = 1;;        if(x<0){            x=x*(-1);            sign = -1;        }                int length=0;        long long result = 0;        int tmp = x;        while(tmp>0){            tmp=tmp/10;            length++;        }        int y;        while(x>0){            length--;            y= x%10;            result += pow(10.0,length) *y ;            x=x/10;        }        result *= sign;        if( result > 2147483647 || result < -2147483647)            return 0;        else            return result ;    }};