Edit Distance

class Solution {
public:
    int minDistance(string word1, string word2) {
        int s1=word1.length()+1;
        int s2=word2.length()+1;
      
        int len[s1][s2];
        int i=0;
        int j=0;
        len[0][0] = 0;
        for(j=1;j<s2;j++)
            len[0][j]=j;
        for(j=1;j<s1;j++)
            len[j][0]=j;  
        for(i=0;i<s1-1;i++)
            for(j=0;j<s2-1;j++){
                if(word1[i] == word2[j]) len[i+1][j+1] = len[i][j];
                else len[i+1][j+1] = min(len[i][j+1],len[i+1][j]) + 1;
                if(len[i+1][j+1] > len[i][j]+1)  len[i+1][j+1]= len[i][j]+1;
            
            }
            return len[s1-1][s2-1];
    }
};