
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.




        >>SOURCE FORMAT FREE
*> This code is dedicated to the public domain
*> This is GNUCOBOL 2.0
identification division.
program-id. beadsort.
environment division.
configuration section.
repository. function all intrinsic.
data division.
working-storage section.
01  filler.
    03  row occurs 9 pic x(9).
    03  r pic 99.
    03  r1 pic 99.
    03  r2 pic 99.
    03  pole pic 99.
    03  a-lim pic 99 value 9.
    03  a pic 99.
    03  array occurs 9 pic 9.
01  NL pic x value x'0A'.
procedure division.
start-beadsort.
 
    *> fill the array
    compute a = random(seconds-past-midnight)
    perform varying a from 1 by 1 until a > a-lim
        compute array(a) = random() * 10
    end-perform
 
    perform display-array
    display space 'initial array'
 
    *> distribute the beads
    perform varying r from 1 by 1 until r > a-lim
        move all '.' to row(r)
        perform varying pole from 1 by 1 until pole > array(r)
            move 'o' to row(r)(pole:1)
        end-perform
    end-perform
    display NL 'initial beads'
    perform display-beads
 
    *> drop the beads
    perform varying pole from 1 by 1 until pole > a-lim
        move a-lim to r2
        perform find-opening
        compute r1 = r2 - 1
        perform find-bead
        perform until r1 = 0 *> no bead or no opening
            *> drop the bead
            move '.' to row(r1)(pole:1)
            move 'o' to row(r2)(pole:1)
            *> continue up the pole
            compute r2 = r2 - 1
            perform find-opening
            compute r1 = r2 - 1
            perform find-bead
        end-perform
    end-perform
    display NL 'dropped beads'
    perform display-beads
 
    *> count the beads in each row
    perform varying r from 1 by 1 until r > a-lim
        move 0 to array(r)
        inspect row(r) tallying array(r)
            for all 'o' before initial '.'
    end-perform
 
    perform display-array
    display space 'sorted array'
 
    stop run
    .
find-opening.
    perform varying r2 from r2 by -1
    until r2 = 1 or row(r2)(pole:1) = '.'
        continue
    end-perform
    .
find-bead.
    perform varying r1 from r1 by -1
    until r1 = 0 or row(r1)(pole:1) = 'o'
        continue
    end-perform
    .
display-array.
    display space
    perform varying a from 1 by 1 until a > a-lim
        display space array(a) with no advancing
    end-perform
    .
display-beads.
    perform varying r from 1 by 1 until r > a-lim
        display row(r)
    end-perform
    .
end program beadsort.