LeetCode Palindrom Number

// Author : yqtao
// Date   : 2016-7-3
// Email  : [email protected]
/**********************************************************************************
* * Determine whether an integer is a palindrome.Do this without extra space.
* * * Some hints :
* * Could negative integers be palindromes ? (ie, -1)
* * If you are thinking of converting the integer to string, note the restriction of using extra space.
* * You could also try reversing an integer.However, if you have solved the problem "Reverse Integer",
*you know that the reversed integer might overflow.How would you handle such case ?
* * There is a more generic way of solving this problem.
* * ********************************************************************************/

#include<iostream>
using namespace std;
//Solutin 1
bool isPalindrome(int x) {
 if (x < 0 || (x != 0 && x % 10 == 0)) {
 return false;
 }
 long long result = 0; //using long long it can not be overflow
 int temp = x;
 while (temp) //revere the num;
 {
 result = result * 10 + temp % 10;
 temp /= 10;
 if (result>INT_MAX) //if overflow ,it must be return false
 return false;
 }
 return x ==result;
}
//Solutin 2 
bool isPalindrome1(int x) {
 if (x < 0 || (x != 0 && x % 10 == 0)) {
 return false;
 }
 int half = 0; 
 while (x > half) { 
 half = half * 10 + x % 10;
 x /= 10;
 }
 if (half == x || half / 10 == x) {
 return true;
 }
 return false;
}
int main()
{
 cout << boolalpha << isPalindrome(121) << endl;
}