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9. Palindrome Number

Solved

Easy

Topics

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Hint

Given an integer x, return true if x is a 

palindrome

, and false otherwise.

 

Example 1:

Input: x = 121
Output: true
Explanation: 121 reads as 121 from left to right and from right to left.

Example 2:

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:

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

 

Constraints:

• -231 <= x <= 231 - 1

 

Follow up: Could you solve it without converting the integer to a string? 

bool isPalindrome(int x) {

    if(x<0||x%10==0&&x!=0) return false;

   

    long int rev =0 ,temp=x;

    while(x !=0)

    {

        rev = rev*10 + x%10 ;

        x /=10;

    }

    //printf("rev=%d x=%d",rev,temp);

    //return (rev == x || x==rev/10);

    return rev ==temp;

}