LeetCode刷题（C++）——Edit Distance（Hard）

Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)

You have the following 3 operations permitted on a word:

a) Insert a character
b) Delete a character
c) Replace a character

class Solution {
public:
    int minDistance(string word1, string word2) {
		int m = word1.length(), n = word2.length();
		vector<vector<int>> dp(m + 1, vector<int>(n + 1));
		for (int i = 0; i <= m;++i) {
			for (int j = 0; j <= n;++j) {
				if (i == 0) {
					dp[i][j] = j;
				}
				else if (j == 0) {
					dp[i][j] = i;
				}
				else {
					dp[i][j] = min(dp[i - 1][j - 1] + ((word1[i - 1] == word2[j - 1]) ? 0 : 1),
						min(dp[i][j - 1] + 1, dp[i - 1][j] + 1)
					);
				}
			}
		}
		return dp[m][n];
    }
};