7. Reverse Integer (整数的溢出）

Reverse digits of an integer.

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

For the purpose of this problem, assume that your function returns 0 when the reversed integer overflows.

int reverse(int x) {
    if(x == INT_MIN){//-2147483648
        return 0;
    }
    
    bool pos = x>= 0? true:false;
    x = abs(x);
    long int ret = 0;
    
    while(x>0){
        ret = ret*10 + x%10;
        if(ret > INT_MAX ) return 0;
        x /= 10;
    }
    if(!pos) ret = 0-ret;
    return ret;
}