/****************************************************************************** * Compilation: javac Comb2.java * Execution: java Comb2 n k * * Enumerates all subsets of size k on n elements. * * % java Comb2 5 3 * 0 1 2 * 0 1 3 * 0 1 4 * 0 2 3 * 0 2 4 * 0 3 4 * 1 2 3 * 1 2 4 * 1 3 4 * 2 3 4 * ******************************************************************************/ public class Comb2 { private static void showCombination(int[] s) { for (int i = 0; i < s.length; i++) StdOut.print(s[i] + " "); StdOut.println(); } public static void generate(int[] s, int position, int nextInt, int k, int n) { if (position == k) { showCombination(s); return; } for (int i = nextInt; i < n; i++) { s[position] = i; generate(s, position + 1, i + 1, k, n); } } public static void main(String[] args) { int n = Integer.parseInt(args[0]); int k = Integer.parseInt(args[1]); int[] s = new int[k]; generate(s, 0, 0, k, n); } }