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LeetCode solutions

1250. Longest Common Subsequence

My accepted Python solution to LeetCode problem 1250, Longest Common Subsequence, running in 461ms.

  • Difficulty: Medium
  • Python
  • Runtime 461ms
  • Memory 42.3MB

Read the problem on LeetCode View on GitHub

The problem statement is LeetCode’s and stays on their site. What follows is my accepted solution.

Python

Accepted on LeetCode — runtime 461ms, memory 42.3MB, accepted 2026-01-02.

python
class Solution:
    def longestCommonSubsequence(self, text1: str, text2: str) -> int:
        m, n = len(text1), len(text2)
        dp = [[0] * (n + 1) for _ in range(m + 1)]
        
        for i in range(1, m + 1):
            for j in range(1, n + 1):
                if text1[i - 1] == text2[j - 1]:
                    dp[i][j] = dp[i - 1][j - 1] + 1
                else:
                    dp[i][j] = max(dp[i - 1][j], dp[i][j - 1])
        
        return dp[m][n]

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