void setup() {
  println(distance("kitten", "sitting"));
}
int distance(String a, String b) {
  int [] costs = new int [b.length() + 1];
  for (int j = 0; j < costs.length; j++)
    costs[j] = j;
  for (int i = 1; i <= a.length(); i++) {
    costs[0] = i;
    int nw = i - 1;
    for (int j = 1; j <= b.length(); j++) {
      int cj = min(1 + min(costs[j], costs[j - 1]), a.charAt(i - 1) == b.charAt(j - 1) ? nw : nw + 1);
      nw = costs[j];
      costs[j] = cj;
    }
  }
  return costs[b.length()];
}