Substring Matching with Prefix and Suffix Scores

Given three strings: text, prefixString, and suffixString, find:

• Prefix score: The longest substring of text that matches the end of prefixString.
• Suffix score: The longest substring of text that matches the start of suffixString.
• Total score: The sum of the prefix score and the suffix score.

Return the substring of text that:

• Begins with the matched prefix.
• Ends with the matched suffix.
• Has the highest total score.

Example

Input:

text = "engine"  
prefixString = "raven"  
suffixString = "ginkgo"  

Processing:

• "engine" matches "raven" at the end, so prefixScore = 2 ("ne").
• "engine" matches "ginkgo" at the start, so suffixScore = 3 ("gin").
• totalScore = 2 + 3 = 5.
• The substring "engin" is selected as it starts with "ne" and ends with "gin".

Output:

"engin"  

Solution Approach

Use dynamic programming to compute the longest common suffix and prefix efficiently.

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Counting Unique Palindromic Substrings

A palindrome is a string that reads the same forwards and backwards, such as "121" or "tacocat".
A substring is a continuous sequence of characters within a string.

Problem

Given a string s, count how many unique substrings of s are palindromes.

Example

Input:

s = "mokkori"  

Distinct Palindromes:

The unique palindromic substrings in "mokkori" are:

1. "m"
2. "o"
3. "k"
4. "kk"
5. "r"
6. "i"
7. "okk"

Output:

7  

Solution Approach

1. Expand Around Centers: For each character (or pair of adjacent characters), expand outwards while maintaining a palindrome.
2. Use a HashSet: Store palindromic substrings to ensure uniqueness.
3. Time Complexity: O(n^2) using a two-pointer expansion method.

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