7.md

Reverse Integer

Reverse digits of an integer.

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

Analysis & Solution

 public int reverse(int x) {
        long res = 0; //need to consider the overflow problem 
        while(x != 0){
            res = res * 10 + x % 10; // -11%10 = -1
            if(res > Integer.MAX_VALUE || res < Integer.MIN_VALUE){
                return 0;
            }
            x = x/10;
        }
        return (int)res;
    }