[leetcode 72] Edit Distance

Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2.

You have the following 3 operations permitted on a word:

1. Insert a character
2. Delete a character
3. Replace a character

Example 1:

Input: word1 = "horse", word2 = "ros" Output: 3

Explanation: horse -> rorse (replace 'h' with 'r') rorse -> rose (remove 'r') rose -> ros (remove 'e')

 

Example 2:

Input: word1 = "intention", word2 = "execution" Output: 5

Explanation: intention -> inention (remove 't') inention -> enention (replace 'i' with 'e') enention -> exention (replace 'n' with 'x') exention -> exection (replace 'n' with 'c') exection -> execution (insert 'u')

 

문제 풀이

- 어렵다...역시 난이도 hard

- 편집 거리 알고리즘 

eazymean.tistory.com/131

[알고리즘] 최소편집거리 알고리즘 edit distance, Levenshtien distance

- 유사한 거리 알고리즘 공부를 열심히 해야겠다...

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

                    }
                }
            }
        }
        
        return dp[n][m];
    }
};