LeetCode 9. Palindrome Number

这道题比上一题还无聊 - -

最后还说不要让我用整数转字符串，那么就reverse好了，如果reverse后相等，就返回true，10分钟的题；

Determine whether an integer is a palindrome. An integer is a palindrome when it reads the same backward as forward.

Example 1:

Input: 121
Output: true

Example 2:

Input: -121
Output: false
Explanation: From left to right, it reads -121. From right to left, it becomes 121-. Therefore it is not a palindrome.

Example 3:

Input: 10
Output: false
Explanation: Reads 01 from right to left. Therefore it is not a palindrome.

Follow up:

Coud you solve it without converting the integer to a string?

AC代码：

class Solution {
public:
    bool isPalindrome(int x) {
        if (x < 0)
            return false;
        long int reverseNum = reverse(x);
        if (x == reverseNum)
            return true;
        else
            return false;
    }
    
    
    int reverse(int x) {
        long int reverseNum = 0;
        
        while(x != 0){
            reverseNum = (reverseNum * 10.0) + x % 10;
            x /= 10;
        }
        
//        if(reverseNum < INT_MAX && reverseNum > INT_MIN)
//            return reverseNum;
//        else
//            return 0;
        return reverseNum;  
    }
};