72.Edit Distance

1 - DP

class Solution {
    public int minDistance(String word1, String word2) {
        int m = word1.length(), n = word2.length();
        int[][] dp = new int[m+1][n+1];
        for(int i = 1; i <= m; i++){
            dp[i][0] = i;
        }
        for(int i = 1; i <= n; i++){
            dp[0][i] = i;
        }
        for(int i = 1; i <= m; i++){
            for(int j = 1; j <= n; j++){
                if(word1.charAt(i - 1) == word2.charAt(j - 1))
                    dp[i][j] = dp[i - 1][j - 1];
                else{
                    int min1 = Math.min(dp[i - 1][j - 1] + 1, dp[i - 1][j] + 1);
                    int min2 = Math.min(min1, dp[i][j - 1] + 1);
                    dp[i][j] = min2;
                }
            }
        }
        return dp[m][n];
    }
}