LeetCode——Edit Distance

Question

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

Solution

动态规划。参见以前的博客：http://www.cnblogs.com/zhonghuasong/p/6147030.html

Code

class Solution {
public:
    int minDistance(string word1, string word2) {
        int len1 = word1.length();
        int len2 = word2.length();
        vector<vector<int>> dp(len1 + 1, vector<int>(len2 + 1, 0));
        for (int i = 0; i <= len1; i++)
            dp[i][0] = i;
        for (int j = 0; j <= len2; j++)
            dp[0][j] = j;
        for (int i = 1; i <= len1; i++) {
            for (int j = 1; j <= len2; j++) {
                int tmp = word1[i - 1] == word2[j - 1] ? 0 : 1;
                dp[i][j] = min(dp[i - 1][j] + 1, min(dp[i][j - 1] + 1, dp[i - 1][j - 1] + tmp));
            }
        }
        return dp[len1][len2];
    }
};