static int levenWithSwapsSubstringIC(S haystack, S needle) {

  int m = strL(needle), n = strL(haystack);

  // base cases

  if (containsIgnoreCase(haystack, needle)) ret 0;

  int[] vx = new int[n+1], v0 = new int[n+1], v1 = new int[n+1];

  for i to m: { // iterate over needle

    v1[0] = i+1;

    for j to n: { // iterate over haystack

      int cost = neqic(needle.charAt(i), haystack.charAt(j)) ? 1 : 0;

      int d = min3(v1[j]+1,       // insertion

                       v0[j+1]+1,   // deletion

                       v0[j]+cost); // substitution

      if (i > 0 && j > 0 && equalsIgnoreCase(needle.charAt(i), haystack.charAt(j-1)) && equalsIgnoreCase(needle.charAt(i-1), haystack.charAt(j)))

        d = min(d, vx[j-1] + 1); // transposition

      v1[j+1] = d;

    }

    int[] temp = vx;

    vx = v0;

    v0 = v1;

    v1 = temp;

  }

  ret minOfIntArray(v0);

}