[LeetCode] [C++] Reverse Integer

1. problem

leetcode.com/problems/reverse-integer/

 

Given integer and return this integer with its digits reverse

(if reversing integer out of range "int", then return 0)

 

2. sol

if x is minus => abs(x)

if x == max, min => return 0

 

push => x%10

pop => x/10

 

class Solution {
public:
    int reverse(int x) {
        int ret = 0,  xx =x;
 
        if(x == INT32_MIN || x == INT32_MAX)
            return 0;
        if(x < 0)
            xx *= -1;
       
        while(xx != 0) {
            int xxx = xx%10;
            xx /= 10;
            if(INT32_MAX/10 < ret)
                return 0;
            ret = ret*10 + xxx;
        }
       
        if(x < 0)
            ret*=-1;
        return ret;
    }
};