7. Reverse Integer

Reverse digits of an integer.

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

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Note: The input is assumed to be a 32-bit signed integer. Your
function should return 0 when the reversed integer overflows.

public class Solution {
    public int reverse(int x) {
        long res = 0;
        int remainder = 0;
        while(x != 0){
            remainder = x%10;
            res = 10*res + remainder;
            x /= 10;
        }

        if(Math.abs(res) > (1<<31) -1) return 0;
        return (int)res;
    }
}