Damerau-Levenshtein distance function in Java

	public static int damLevDist(String A, String B) {
		StringBuilder builder = new StringBuilder();
		builder.append("  ");
		A = A.toLowerCase(); B = B.toLowerCase();
		int alen = A.length(), blen = B.length();
		int maxdist = alen + blen;
		int alphabet[] = new int[127];
		for (int i = 0; i < alphabet.length; ++i) {
			alphabet[i] = 0;
		}
		int H[][] = new int[alen + 2][blen + 2];
		H[0][0] = maxdist;
		for (int i = 0; i < alen; ++i) {
			H[i][0] = maxdist;
			H[i][1] = i;
		}
		for (int i = 0; i < blen; ++i) {
			H[0][i] = maxdist;
			H[1][i] = i;
			builder.append("  ");
			builder.append(B.charAt(i));
		}
		builder.append('\n');
		for (int a = 2; a < alen + 2; ++a) {
			int lastMatchIndex = 0;
			char ca = A.charAt(a-2);
			builder.append(ca);
			builder.append(' ');
			for (int b = 2; b < blen + 2; ++b) {
				char cb = B.charAt(b-2);
				int row = alphabet[cb];
				int col = lastMatchIndex;
				int cost = ca ==cb ? 0 : 1;
				if (cost == 0) {
					lastMatchIndex = b;
				}
				int w = min(
							H[a-1][b-1] + cost,
							H[a][b-1] + 1,
							H[a-1][b] + 1,
							H[row][col] + (a-2-row) + 1 + (b-2-col)
						);
				H[a][b] = w;
				if (w <= 9)  { builder.append(' '); }
				if (w <= 99) { builder.append(' '); }
				builder.append(String.valueOf(w));
			}
			builder.append('\n');
			alphabet[ca] = a-1;
		}
		System.out.println(builder);
		return H[alen+1][blen+1];
	}