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?


num < 2 ** 31

Example 1

num = 121


Example 2

num = 20200202


Example 3

num = 43


Solution :


                        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
            return False

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