/* Algorithm 4.11: Procedure Next for permutations in lexicographic order. */

#include <stdio.h>
#include <stdlib.h>

#define MAX 12

int A[MAX];
int n;

enum BOOLEAN {FALSE, TRUE};
enum BOOLEAN done;

void PrintIt() {
  int i;

  for (i=1; i <= n ; i ++)
    printf(" %d", A[i]);

  printf("\n");
}

void Next(void) {
  int k, j, r, s, tmp;

  k = n-1;

  while (A[k] > A[k+1])
    k --;

  if (k == 0)
    done = TRUE;
  else {
    j = n;
    while (A[k] > A[j])
      j --;
    tmp = A[j];
    A[j] = A[k];
    A[k] = tmp;

    r = n, s = k+1;

    while (r > s) {
      tmp = A[r];
      A[r] = A[s];
      A[s] = tmp;
      r--, s++;
    }
  }
}

int main(int argc, char* argv []) {
  int i;

  if (argc != 2) {
    printf("\n A single arguments expected.\n");
    return 1;
  }

  n = atoi(argv[1]);

  if (n < 0) {
    printf("\n Positive number expected.\n");
    return 2;
  }

  if (n > MAX) {
    printf("\n The argument cannot be not greater than %d.\n", MAX);
    return 3;
  }

  done = FALSE;
  for (i=0; i <= n; i ++)
    A[i] = i;
  
  /*  Main loop  */
  do {
    PrintIt();
    Next(); }
  while (!done);

  return 0;
}