using System; class Permutations { static int n = 4; static int [] buf = new int [n]; static bool [] used = new bool [n]; static void Main() { for (int i = 0; i < n; i++) used [i] = false; rec(0); } static void rec(int ind) { for (int i = 0; i < n; i++) { if (!used [i]) { used [i] = true; buf [ind] = i; if (ind + 1 < n) rec(ind + 1); else Console.WriteLine(string.Join(",", buf)); used [i] = false; } } } }