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 :
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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