WAP to check a given string is Palindrome or Not
Objective
Write a C++ program to check if a string is a Palindrome.
Algorithm / Approach
- Read a string into
s1. - Make a backup copy:
s2 = s1. - Reverse the original string:
reverse(s1.begin(), s1.end()). - Compare the modified original to the backup:
if (s1 == s2). - If they match, it is a palindrome.
main.cpp
#include<iostream>
#include< algorithm>
using namespace std;
int main() {
string s1,s2;
cout<<"Enter a string : ";
getline(cin,s1);
s2 = s1;
reverse(s1.begin(),s1.end());
if(s1==s2) {
cout<<"String is Palindrome";
}
else {
cout<<"String is not Palindrome";
}
return 0;
}Expected Output
Enter a string : cprowess String is not Palindrome
Explanation of the Program
- A palindrome string reads identically forwards and backwards (e.g., "racecar").
- By using the C++ standard library features we've already learned (string assignment, the
reverse()algorithm, and the==operator), checking for a palindrome becomes a trivial 4-line task.
Complexity
Time Complexity
O(n)
Space Complexity
O(n)
