Longest Common Subsequence $($LCS$)$ Using Dynamic Programming

Given two sequences, find the length of the longest subsequence present in both of them. A subsequence is a sequence that appears in the same relative order but not necessarily consecutively.

Input:

Two strings X and Y of lengths m and n$,$ respectively.

Output:

The length of their longest common subsequence.

Optionally, print the longest common subsequence itself.

Example:

For the input strings X $=$ "AGGTAB" and Y $=$ "GXTXAYB",

The length of the LCS is $4("$GTAB$"$ is the longest common subsequence$).$