edit distance.java

public class Solution {
    
    private int min (int a, int b, int c) {
        if (a <= b && a <= c)
            return a;
        else if (b <=a && b <= c)
            return b;
        else
            return c;
    }
    
    public int minDistance(String word1, String word2) {
        int len1 = word1.length();
        int len2 = word2.length();
        int[][] arr = new int[len1 + 1][len2 + 1];
        arr[0][0] = 0;
        for (int i = 1; i <= len1; i++) {
            arr[i][0] = i;
        }
        for (int j = 1; j <= len2; j++) {
            arr[0][j] = j;
        }
        for (int i = 0; i < len1; i++) {
            for (int j = 0; j < len2; j++) {
                int cost = arr[i][j];
                if (word1.charAt(i) != word2.charAt(j)) {
                    cost++;
                }
                arr[i + 1][j + 1] = min(arr[i][j + 1] + 1, arr[i + 1][j] + 1, cost);
            }
        }
        return arr[len1][len2];
    }
}