Leetcode edit distance

Given two wordsWord1AndWord2, Find the minimum number of steps required to convertWord1ToWord2. (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

Enter word1 and word2 to find the minimum steps for converting from word1 to word2. One step for each conversion operation. The conversion operation is limited:

• Delete a character
• Insert a character
• Replace one character

This question is solved using dynamic planning

Set the decision variable DP [I] [J] to represent the minimal step from word [0 .. I-1] To word2 [0 .. J-1]

See http://web.stanford.edu/class/cs124/lec/med.pdf

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