Edit Distance

DP的一题

d[i, j] = 最小值(
d[i-1, j ] + 1, // 刪除
d[i , j-1] + 1, // 插入
d[i-1, j-1] + {0,1}  // 替換

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