7.整数反转0ms

class Solution {
    public int reverse(int x) {
        int res = 0;
        while(x!=0){
            res = res*10+x%10;
            // 判断整数溢出
            if(res%10!=x%10){
                return 0;
            }
            x=x/10;
        }
        return res;
    }
}