Added Longest Palindromic Substring and Min Insertions/Deletions C++ programs

[Srisilpa]

Description:

This PR adds two new C++ programs under the DSA/Strings directory:

1. Longest Palindromic Substring (DSA/Strings/longestPalindromicSubstring.cpp)

   • Finds the longest contiguous substring which is a palindrome.
   • Uses expand-around-center approach for efficiency.
   • Includes comments and sample input/output.

2. Minimum Insertions/Deletions to Make a String Palindrome (DSA/Strings/min_insertions_deletions_palindrome.cpp)

   • Calculates minimum insertions and deletions required to make a string a palindrome.
   • Uses Longest Palindromic Subsequence (LPS) via LCS logic.
   • Includes comments and sample input/output.

📄 References:

• Longest Palindromic Substring: https://en.wikipedia.org/wiki/Longest_palindromic_substring
• Minimum Insertions/Deletions: https://www.geeksforgeeks.org/minimum-insertions-to-form-a-palindrome/

Example:

Longest Palindromic Substring
Input: "babad"
Output: "bab" or "aba"

Minimum Insertions/Deletions
Input: "abcda"
Output:

• Minimum Insertions: 2
• Minimum Deletions: 2

[vercel]

@Srisilpa is attempting to deploy a commit to the Evgenii-Bazhaov Team on Vercel.

A member of the Team first needs to authorize it.

[Srisilpa]

Hi Maintainers,

My contribution adds two C++ programs under DSA/Strings:

1. Longest Palindromic Substring
2. Minimum Insertions/Deletions to Make a String Palindrome

The Vercel deployment check is failing due to authorization issues (it’s for web deployment), but it does not affect these C++ programs.

Everything else has been tested and is ready for review/merge.

Thank you!