Check if String formed by first and last X characters of a String is a Palindrome

Check if String formed by first and last X characters of a String is a Palindrome

Given a string str and an integer X. The task is to find whether the first X characters of both string str and reversed string str are same or not. If it is equal then print true, otherwise print false.

Examples:

Input: str = abcdefba, X = 2
Output: true
Explanation: 
First 2 characters of both string str and reversed string str are same.

Input: str = GeeksforGeeks, X = 3
Output: false

Approach: This problem can be solved by iterating over the characters of the string str. Follow the steps below to solve this problem: 

• Initialize two variables say, i as 0 and n as length of str to store position of current character and length of the string str respectively.
• Iterate while i less than n and x:
  • If ith character from starting and ith from the last are not equal, then print false and return.
• After completing the above steps, print true as the answer.

Below is the implementation of the above approach : 

C++

#include <bits/stdc++.h> using namespace std;    void isEqualSubstring(string str, int x) {          int n = str.length();     int i = 0;                       while (i < n && i < x) {                              if (str[i] != str[n - i - 1]) {             cout << "false";             return;         }         i++;     }             cout << "true"; }    int main() {          string str = "GeeksforGeeks";     int x = 3;             isEqualSubstring(str, x); }

Output

false

Time complexity: O(min(n, k))
Auxiliary Space: O(1)

Attention reader! Don’t stop learning now. Get hold of all the important DSA concepts with the DSA Self Paced Course at a student-friendly price and become industry ready.  To complete your preparation from learning a language to DS Algo and many more,  please refer Complete Interview Preparation Course.

In case you wish to attend live classes with industry experts, please refer DSA Live Classes 

Adblock test (Why?)

Original page link

Best Cool Tech Gadgets

Top favorite technology gadgets