
Sorting Algorithm

This is a sorting algorithm.   It may be applied to a set of data in order to sort it.    
For comparing various sorts, see compare sorts.  
For other sorting algorithms,   see sorting algorithms,   or:

O(n logn) sorts
Heap sort |
Merge sort |
Patience sort |
Quick sort
O(n log2n) sorts
Shell Sort
O(n2) sorts
Bubble sort |
Cocktail sort |
Cocktail sort with shifting bounds |
Comb sort |
Cycle sort |
Gnome sort |
Insertion sort |
Selection sort |
Strand sort
other sorts
Bead sort |
Bogo sort |
Common sorted list |
Composite structures sort |
Custom comparator sort |
Counting sort |
Disjoint sublist sort |
External sort |
Jort sort |
Lexicographical sort |
Natural sorting |
Order by pair comparisons |
Order disjoint list items |
Order two numerical lists |
Object identifier (OID) sort |
Pancake sort |
Quickselect |
Permutation sort |
Radix sort |
Ranking methods |
Remove duplicate elements |
Sleep sort |
Stooge sort |
[Sort letters of a string] |
Three variable sort |
Topological sort |
Tree sort


Task

Sort an array of positive integers using the Bead Sort Algorithm.

A   bead sort   is also known as a   gravity sort.



Algorithm has   O(S),   where   S   is the sum of the integers in the input set:   Each bead is moved individually.

This is the case when bead sort is implemented without a mechanism to assist in finding empty spaces below the beads, such as in software implementations.




#include <stdio.h>
#include <stdlib.h>
 
void bead_sort(int *a, int len)
{
	int i, j, max, sum;
	unsigned char *beads;
#	define BEAD(i, j) beads[i * max + j]
 
	for (i = 1, max = a[0]; i < len; i++)
		if (a[i] > max) max = a[i];
 
	beads = calloc(1, max * len);
 
	/* mark the beads */
	for (i = 0; i < len; i++)
		for (j = 0; j < a[i]; j++)
			BEAD(i, j) = 1;
 
	for (j = 0; j < max; j++) {
		/* count how many beads are on each post */
		for (sum = i = 0; i < len; i++) {
			sum += BEAD(i, j);
			BEAD(i, j) = 0;
		}
		/* mark bottom sum beads */
		for (i = len - sum; i < len; i++) BEAD(i, j) = 1;
	}
 
	for (i = 0; i < len; i++) {
		for (j = 0; j < max && BEAD(i, j); j++);
		a[i] = j;
	}
	free(beads);
}
 
int main()
{
	int i, x[] = {5, 3, 1, 7, 4, 1, 1, 20};
	int len = sizeof(x)/sizeof(x[0]);
 
	bead_sort(x, len);
	for (i = 0; i < len; i++)
		printf("%d\n", x[i]);
 
	return 0;
}