Solution: Longest Common Subsequence
Explore how to solve the longest common subsequence problem by applying dynamic programming techniques. Understand the difference between naive and optimized approaches, and learn how memoization and a 2D table improve time complexity from exponential to polynomial. This lesson teaches you to efficiently compute subsequence length while managing recursion with memoization for better performance.
Statement
Suppose you are given two strings. You need to find the length of the longest common subsequence between these two strings.
A subsequence is a string formed by removing some characters from the original string while maintaining the relative position of the remaining characters. For example, “abd” is a subsequence of “abcd”, where the removed character is “c”.
If there is no common subsequence, then return 0.
Constraints:
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str1.length