【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

 

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;i++) f[i][0]=i;
        for(int j=0;j<=len2;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];
                else{
                    int tmp=min(f[i-1][j],f[i][j-1]);
                    f[i][j]=min(tmp,f[i-1][j-1])+1;
                }

            }
        }

        return f[len1][len2];
    }
};