Solution: Longest Common Subsequence
Explore how to solve the longest common subsequence problem using dynamic programming. Understand the top-down memoization technique to optimize recursive solutions by storing subproblem results in a 2D table. Learn to improve time complexity from exponential to polynomial, and manage space complexity effectively for coding interviews.
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