/*
 * bubble.c
 * This program reads a sequence of intergers, terminated by (-1), and sorts
 * it using the bubble-sort algorithm.
 */

#include <stdio.h>

#define MAX_SIZE 100

/* Prototypes: */
void bubble_sort (int *arr, int n);

int main ()
{
  const int stop_code = -1;
  int       array[MAX_SIZE];
  int       n_numbers = 0;
  int       curr;
  int       i;

  /* Read the input numbers. */
  while (n_numbers < MAX_SIZE)
  {
    /* Read the next number. */
    printf ("Please enter the next number (or -1 to stop): ");
    scanf ("%d", &curr);

    if (curr == stop_code)
      break;

    /* Store it. */
    array[n_numbers] = curr;
    n_numbers++;
  }

  /* Sort the numbers and print them. */
  bubble_sort (array, n_numbers);

  for (i = 0; i < n_numbers; i++)
    printf ("%d ", array[i]);
  printf ("\n");

  return (0);
}

/* ------------------------------------------------------------------------
 * Function: bubble_sort
 * Purpose : Sort an array of integers in an ascending order, using the
 *           bubble-sort algorithm.
 * Input   : n   - The number of intergers in the array.
 * In/Out  : arr - The array.
 * Returns : Nothing.
 */
void bubble_sort (int *arr, int n)
{
  int     i, j;
  int     temp;

  /* Let i run over all entries (except the last). */
  for (i = 0; i < n - 1; i++)
  {
    /* Let j run over all entries from (i+1) until the last. */
    for (j = i + 1; j < n; j++)
    {
      /* If arr[i] > arr[j], swap the two entries. */
      if (arr[i] > arr[j])
      {
        temp = arr[i];
        arr[i] = arr[j];
        arr[j] = temp;
      }
    }
  }

  return;
}