题目：

题解：

func minDistance(word1 string, word2 string) int {
	m, n := len(word1), len(word2)
	dp := make([][]int, m+1)
	for i := range dp {
		dp[i] = make([]int, n+1)
	}
	for i := 0; i < m+1; i++ {
		dp[i][0] = i // word1[i] 变成 word2[0], 删掉 word1[i], 需要 i 部操作
	}
	for j := 0; j < n+1; j++ {
		dp[0][j] = j // word1[0] 变成 word2[j], 插入 word1[j]，需要 j 部操作
	}
	for i := 1; i < m+1; i++ {
		for j := 1; j < n+1; j++ {
			if word1[i-1] == word2[j-1] {
				dp[i][j] = dp[i-1][j-1]
			} else { // Min(插入，删除，替换)
				dp[i][j] = Min(dp[i][j-1], dp[i-1][j], dp[i-1][j-1]) + 1
			}
		}
	}
	return dp[m][n]
}
func Min(args ...int) int {
	min := args[0]
	for _, item := range args {
		if item < min {
			min = item
		}
	}
	return min
}