72. 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 m=word1.size(),n=word2.size();        if(m==0)return n;        if(n==0)return m;        vector<vector<int>>dp(m+1,vector<int>(n+1));        for(int i=0;i<=m;++i)        {            for(int j=0;j<=n;++j)            {                if(j==0)                {                  dp[i][j]=i;                }                else if(i==0)                dp[i][j]=j;                else                dp[i][j]=min(dp[i-1][j-1]+(word1[i-1]==word2[j-1]?0:1),min(dp[i-1][j]+1,dp[i][j-1]+1));            }        }        return dp[m][n];    }};