LeetCode Edit Distance

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

 

 1 public class Solution {
 2     public int minDistance(String word1, String word2) {
 3         if (word1.equals(word2)) {
 4             return 0;
 5         }
 6         if (word1.length()==0) {
 7             return word2.length();
 8         }
 9         if (word2.length()==0) {
10             return word1.length();
11         }
12         
13         int[][] distance=new int[word1.length()+1][word2.length()+1];
14         for (int i = 0; i <= word1.length(); i++) {
15             distance[i][0]=i;
16         }
17         for (int i = 0; i <= word2.length(); i++) {
18             distance[0][i]=i;
19         }
20         
21         for (int i = 1; i <= word1.length(); i++) {
22             for (int j = 1; j <= word2.length(); j++) {
23                 if (word1.charAt(i-1)==word2.charAt(j-1)) {
24                     distance[i][j]=distance[i-1][j-1];
25                 }else {
26                     distance[i][j]=Math.min(Math.min(distance[i-1][j], distance[i][j-1]), distance[i-1][j-1])+1;
27                 }
28             }
29             
30         }
31         return distance[word1.length()][word2.length()];
32     }
33 }

 

posted @ 2015-01-27 20:41  birdhack  阅读(140)  评论(0)  编辑  收藏  举报