Edit Distance

EditDistance.java

int getEditDistance(String a, String b) {
    int[][] distances = new int[a.length()][b.length()];

    for(int i = 0; i < distances.length; i++) {
        distances[i][0] = i;
    }

    for(int j = 0; j < distances[0].length; j++) {
        distances[0][j] = j;
    }

    for(int i = 1; i < a.length(); i++) {
        for(int j = 1; j < b.length(); j++) {
            int dist1 = distances[i - 1][j - 1];
            if(a.charAt(i) != b.charAt(j)) {
                dist1 += 2;
            }

            int dist2 = distances[i - 1][j] + 1;
            int dist3 = distances[i][j - 1] + 1;

            distances[i][j] = Math.min(dist1, Math.min(dist2, dist3));
        }
    }

    return distances[a.length() - 1][b.length() - 1];
}