7. 整数反转

//有符号整数溢出：964632435*10不能用类型“int”表示
//1534236469
int reverse(int x){
    long int y = 0;
    while (x != 0) {  
        y = (x % 10)+ y * 10;
        x /= 10;
        if (y > INT_MAX || y < INT_MIN) {
            return 0;
        }
    }
    return y;
}

class Solution:
    def reverse(self, x: int) -> int:
        y = 0
        if x < 0:
            x = -x
            while x != 0:
                y = y * 10 + (x % 10)
                x //= 10
                if y > 2**31 - 1 or y < -2**31:
                    return 0
            return -y
        while x != 0:
            y = y * 10 + (x % 10)
            x //= 10
            if y > 2**31 - 1 or y < -2**31:
                return 0    
        return y