Longest Common Subsequence
Given two strings word1 and word2, return the length of their longest common subsequence. This is often called Two Sequence Alignment Problem.
A subsequence of a string is a new string generated from the original string with some characters(can be none) deleted without changing the relative order of the remaining characters. (eg, "ace" is a subsequence of "abcde" while "aec" is not). A common subsequence of two strings is a subsequence that is common to both strings.
If there is no common subsequence, return 0.
Example 1:
Input:
1word1 = "abcde" 2word2 = "ace"
Output: 3
Explanation:
The longest common subsequence is ace and its length is 3.
Example 2:
Input:
1word1 = "almost" 2word2 = "algomonster"
Output: 6
Explanation:
The longest common subsequence is almost and its length is 6.
Example 3:
Input:
1word1 = "abc" 2word2 = "def"
Output: 0
Explanation:
There is no such common subsequence, so the result is 0.