LeetCode: Edit Distance

思路：很经典的动态规划方法，练练手，实现的速度还可以，注意下标的选择问题（我是没有选好，挂了一次）

class Solution {public:    int minDistance(string word1, string word2) {int len1 = word1.length(), len2 = word2.length();int ** f = new int* [len1+1];for(int i = 0;i < len1+1;i++)f[i] = new int[len2+1];for(int i =0;i<len1+1;i++)f[i][0] = i;for(int j=0;j<len2+1;j++)f[0][j] = j;for(int i=1;i<=len1;i++)for(int j=1;j<=len2;j++){if(word1[i-1] == word2[j-1])f[i][j] = f[i-1][j-1];elsef[i][j] = min(min(f[i-1][j],f[i][j-1]),f[i-1][j-1]) + 1;}return f[len1][len2];    }};