python-leetcode-编辑距离

72. 编辑距离 - 力扣（LeetCode）

class Solution:
    def minDistance(self, word1: str, word2: str) -> int:
        m, n = len(word1), len(word2)
        dp = [[0] * (n + 1) for _ in range(m + 1)]

        # 初始化
        for i in range(m + 1):
            dp[i][0] = i  # 只能删除
        for j in range(n + 1):
            dp[0][j] = j  # 只能插入

        # 填充 dp 表
        for i in range(1, m + 1):
            for j in range(1, n + 1):
                if word1[i - 1] == word2[j - 1]:  # 相等，无需额外操作
                    dp[i][j] = dp[i - 1][j - 1]
                else:  # 选择插入、删除、替换操作中的最小值
                    dp[i][j] = min(dp[i - 1][j] + 1,   # 删除
                                dp[i][j - 1] + 1,   # 插入
                                dp[i - 1][j - 1] + 1)  # 替换
        return dp[m][n]