LeetCode: Reverse Integer

一次过

class Solution {
public:
    int reverse(int x) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        bool isNeg = x < 0;
        x = abs(x);
        int ret = 0;
        while (x) {
            ret = ret * 10 + x % 10;
            x /= 10;
        }
        return isNeg? -ret : ret;
    }
};

 C#

public class Solution {
    public int Reverse(int x) {
        bool neg = x < 0;
        if (x == Int32.MinValue) x = Int32.MaxValue;
        else x = Math.Abs(x);
        int ans = 0;
        while (x > 0) {
            if (ans > (Int32.MaxValue - x % 10) / 10) return 0;
            ans = ans * 10 + x % 10;
            x /= 10;
        }
        return neg? -ans : ans;
    }
}