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Module DEMO-32-59DEMO-C-32

Palindrome Number Checker using while

DEMO-C-32 • Programming in C

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Problem Statement

Write a C program that determines whether a given integer is a palindrome. A palindrome number reads the same backward as forward (e.g., 121, 1331, 7).

Your program should read an integer from standard input and output one of the following messages:

  • "PALINDROME" if the number is a palindrome
  • "NOT PALINDROME" if the number is not a palindrome

Important Requirements:

  • You must use loops only (no recursion)
  • You cannot convert the number to a string
  • You must handle negative numbers appropriately (negative numbers are not palindromes)
  • You must handle the special case of 0 correctly

Examples:

  • 121 → PALINDROME
  • -121 → NOT PALINDROME
  • 123 → NOT PALINDROME
  • 0 → PALINDROME
  • 1001 → PALINDROME

Input Format

A single integer N on standard input (-1000000 ≤ N ≤ 1000000)

Output Format

Print exactly one line containing either "PALINDROME" or "NOT PALINDROME" (without quotes)

Sample Testcases

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Sample #1
Public sample
Input
121
Output
PALINDROME
Explanation
121 reads the same forwards and backwards, so it's a palindrome
Sample #2
Public sample
Input
0
Output
PALINDROME
Explanation
0 is considered a palindrome
Sample #3
Public sample
Input
123
Output
NOT PALINDROME
Explanation
123 does not read the same forwards and backwards, so it's not a palindrome
Sample #4
Public sample
Input
-121
Output
NOT PALINDROME
Explanation
Negative numbers are not considered palindromes

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