Palindromic Integer - Amazon Top Interview Questions


Problem Statement :


Given a non-negative integer num, return whether it is a palindrome.

Bonus: Can you solve it without using strings?

Constraints

num < 2 ** 31


Example 1

Input
num = 121


Output
True


Example 2

Input
num = 20200202

Output
True


Example 3

Input
num = 43

Output
False


Solution :



title-img 




                        Solution in C++ :

bool solve(int num) {
    int t = num;
    int rev = 0;
    while (t) {
        rev = rev * 10 + t % 10;
        t = t / 10;
    }
    if (rev == num) {
        return true;
    }
    return false;
}
                    


                        Solution in Java :

import java.util.*;

class Solution {
    public boolean solve(int num) {
        if (num < 0 || (num != 0 && num % 10 == 0))
            return false;

        int rev = 0;
        while (num > rev) {
            rev = rev * 10 + num % 10;
            num = num / 10;
        }
        return (num == rev || num == rev / 10);
    }
}
                    


                        Solution in Python : 
                            
class Solution:
    def solve(self, num):
        a = 0
        c = num
        while num > 0:
            r = num % 10
            num = num // 10
            a = (10 * a) + r
        if a == c:
            return True
        else:
            return False


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