9.palindrome-number.0.cpp

/*
 * [9] Palindrome Number
 *
 * https://leetcode.com/problems/palindrome-number/description/
 *
 * algorithms
 * Easy (36.00%)
 * Total Accepted:    326.1K
 * Total Submissions: 905.4K
 * Testcase Example:  '121'
 *
 * 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?
 * 
 */
class Solution {
public:
    bool isPalindrome(int x) {
		if(x == 0)
		  return true;
		if(x < 0 || x % 10 == 0)
		  return false;

		int temp = 0;
		while(temp < x){
			temp  = 10*temp + x%10;
			x /= 10;
		}
		if(x == temp || x == temp/10)
		  return true;
		else
		  return false;
    }
};