标签:style blog http color java io strong for
题目:
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 characterc) Replace a character
题解:
处理这道题也是用动态规划。
动态数组dp[word1.length+1][word2.length+1]
dp[i][j]表示从word1前i个字符转换到word2前j个字符最少的步骤数。
假设word1现在遍历到字符x,word2遍历到字符y(word1当前遍历到的长度为i,word2为j)。
以下两种可能性:
1. x==y,那么不用做任何编辑操作,所以dp[i][j] = dp[i-1][j-1]
2. x != y
(1) 在word1插入y, 那么dp[i][j] = dp[i][j-1] + 1
(2) 在word1删除x, 那么dp[i][j] = dp[i-1][j] + 1
(3) 把word1中的x用y来替换,那么dp[i][j] = dp[i-1][j-1] + 1
最少的步骤就是取这三个中的最小值。
最后返回 dp[word1.length+1][word2.length+1] 即可。
代码如下:
Reference:
http://www.programcreek.com/2013/12/edit-distance-in-java/
http://blog.csdn.net/linhuanmars/article/details/24213795
Edit Distance leetcode java,布布扣,bubuko.com
标签:style blog http color java io strong for
原文地址:http://www.cnblogs.com/springfor/p/3896167.html