Palindrome Number Problem


Description

LeetCode Problem 9.

Given an integer x, return true if x is palindrome integer.

An integer is a palindrome when it reads the same backward as forward. For example, 121 is palindrome while 123 is not.

Example 1:

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Input: x = 121
Output: true

Example 2:

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Input: x = -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:

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

Example 4:

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Input: x = -101
Output: false

Constraints:

  • -2^31 <= x <= 2^31 - 1


Sample C++ Code

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class Solution {
public:
    bool isPalindrome(int x) {
        if (x<0|| (x!=0 &&x%10==0)) return false;
        int sum=0;
        while (x>sum)
        {
            sum = sum*10+x%10;
            x = x/10;
        }
        return (x==sum)||(x==sum/10);
    }
};




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