Grokking Dynamic Programming Patterns for Coding Interviews

Solution: Longest Palindromic Substring

## Problem Statement
Given a string, find the length of its Longest Palindromic Substring (LPS). In a palindromic string, elements read the same backward and forward.

**Example 1:**
```
Input: "abdbca"
Output: 3
Explanation: LPS is "bdb".
```

**Example 2:**
```
Input: = "cddpd"
Output: 3
Explanation: LPS is "dpd".
```

**Example 3:**
```
Input: = "pqr"
Output: 1
Explanation: LPS could be "p", "q" or "r".
```

**Constraints:**

- `1 <= st.length <= 1000`
- `st` consists only of lowercase English letters.

## Basic Solution
This problem follows the `"Longest Palindromic Subsequence"` pattern