Data Structure
Networking
RDBMS
Operating System
Java
MS Excel
iOS
HTML
CSS
Android
Python
C Programming
C++
C#
MongoDB
MySQL
Javascript
PHP
Physics
Chemistry
Biology
Mathematics
English
Economics
Psychology
Social Studies
Fashion Studies
Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
C Program to check if an array is palindrome or not using Recursion
Given an array arr[n] where n is some size of an array, the task is to find out that the array is palindrome or not using recursion. Palindrome is a sequence which can be read backwards and forward as same, like: MADAM, NAMAN, etc.
So to check an array is palindrome or not so we can traverse an array from back and forward like −
In recursion also we have to change the start and end value till they are equal or when the values as start and end are not equal then exit and return false that the given array is not palindrome.
Example
Input: arr[] = { 2, 3, 4, 3, 2}
Output: Yes, the array is Palindrome
Explanation: the array is identical from start (2, 3, 4, 3, 2) and end (2, 3, 4, 3, 2).
Input: arr[] = {1, 2, 3, 4}
Output: No, the array is not Palindrome
Explanation: The array is not identical from start (1, 2, 3, 4) and end (4, 3, 2, 1).Approach used below is as follows −
We will recursively do the following steps −
- Check arr[start] is equal to arr[end] and start < end
- Increment start with 1 and decrement end with 1.
- Goto step 1.
Algorithm
Start
In function int palindrome(int arr[], int start, int end)
Step 1-> If start >= end then,
Return 1
Step 2-> If arr[start] == arr[end] then,
Return palindrome(arr, start + 1, end - 1)
Step 3-> Else {
Return 0
In fucntion int main()
Step 1-> Declare and initialize an array arr[]
Step 2-> Declare and initialize n = sizeof(arr) / sizeof(arr[0]
Step 3-> If palindrome(arr, 0, n - 1) == 1 then,
Print "Yes, the array is Palindrome”
Step 4-> Else
Print "No, the array is not Palindrome”
StopExample
#include <stdio.h>
// Recursive pallindrome function that returns 1 if
// palindrome, 0 if it is not
int palindrome(int arr[], int start, int end) {
// base case
if (start >= end) {
return 1;
}
if (arr[start] == arr[end]) {
return palindrome(arr, start + 1, end - 1);
} else {
return 0;
}
// Driver code
int main() {
int arr[] = { 1, 2, 0, 2, 1 };
int n = sizeof(arr) / sizeof(arr[0]);
if (palindrome(arr, 0, n - 1) == 1)
printf("Yes, the array is Palindrome
");
else
printf("No, the array is not Palindrome
");
return 0;
}Output
If run the above code it will generate the following output −
Yes, the array is Palindrome
Updated on: 21-Oct-2019
1K+ Views
Advertisements