generateLists.c

#include <stdio.h>

void swap(int *num1, int *num2) { // standard swap function
  int temp; // temporary var

  temp = *num1;  // store to temp
  *num1 = *num2; // swap it
  *num2 = temp;  // swap it again :D
}

int rearange(int *numbers, int index, int num, int fact) {
  swap(&numbers[index], &numbers[index-1]); // swap number at index with the one behind it

  /*int temp = numbers[index];
  numbers[index] = numbers[index-1];
  numbers[index-1] = temp;*/

  int i;
  for (i = 1; i <= num; ++i) // print the current sequence
  {
    printf("%d ", numbers[i]);
  }
  printf("\n");

  fact--;  // decrement how many sequences remain
  index--; // decrement our index in the array

  if (index > 1) {
    if (fact > 0)                                                       // If we have more sequences remaining
       rearange(numbers, index, num, fact);
  } else {
    return fact;
  }// Do it all again! :D
}

int main() {
  int num, i; // our number and a counter

  printf("Enter a number less than 10: ");
  scanf("%d", &num); // get the number from the user

  int numbers[11]; // create an array of appropriate size
  // fill array
  for (i = 1; i <= num; i++) { // fill the array from 1 to num
    numbers[i] = i;
  }

  int fact = 1; // calculate the factorial to determine
  for (i = 1; i <= num; ++i) // how many possible sequences
  {
    fact = fact * i;
  }

  do {
    fact = rearange(numbers, num, num, fact);
  } while (fact > 0);

  //rearange(numbers, num, num, fact); // begin rearranging by recursion

  return 0;
}