Sorting algorithms/Counting sort: Difference between revisions

=={{header|REXX}}==

<lang rexx>

/*REXX program sorts an array using the count-sort method. */

call gen@ /*generate array elements. */

call show@ 'before sort' /*show before array elements*/

call countSort highItem /*invoke the count sort. */

call show@ ' after sort' /*show after array elements*/

exit

/*─────────────────────────────────────countSORT subroutine────────*/

countSort: procedure expose @.; parse arg n

h=@.1

L=h

do m=2 to n

L=min(L,@.m)

h=max(h,@.m)

end

_.=0

do j=1 for n

k=@.j

_.k=_.k+1

end

#=1

do j=L to h

if _.j\==0 then do #=# for _.j

@.#=j

end

end

return

/*─────────────────────────────────────GEN@ subroutine─────────────*/

gen@: @.='' /*assign default value. */

/* get the first 40 Recaman numbers: subtract if you can, */

/* otherwise add. Another way: Recaman(1) = 1, */

/* Recaman(n) = Recaman(n-1)-n if positive and new, else */

/* Recaman(n) = Recaman(n-1)+n */

@.1 = 1

@.2 = 3

@.3 = 6

@.4 = 2

@.5 = 7

@.6 = 13

@.7 = 20

@.8 = 12

@.9 = 21

@.10= 11

@.11= 22

@.12= 10

@.13= 23

@.14= 9

@.15= 24

@.16= 8

@.17= 25

@.18= 43

@.19= 62

@.20= 42

@.21= 63

@.22= 41

@.23= 18

@.24= 42

@.25= 17

@.26= 43

@.27= 16

@.28= 44

@.29= 15

@.30= 45

@.31= 14

@.32= 46

@.33= 79

@.34= 113

@.35= 78

@.36= 114

@.37= 77

@.38= 39

@.39= 78

@.40= 38

do highItem=1 while @.highItem\=='' /*find how many entries. */

end

highItem=highItem-1 /*adjust highItem slightly. */

return

/*─────────────────────────────────────SHOW@ subroutine────────────*/

show@: widthH=length(highItem) /*maximum width of any line.*/

do j=1 for highItem

say 'element' right(j,widthH) arg(1)":" @.j

end

say copies('─',80) /*show a seperator line. */

return

</lang>

Output:

<pre style="height:30ex;overflow:scroll">

element 1 before sort: 1

element 2 before sort: 3

element 3 before sort: 6

element 4 before sort: 2

element 5 before sort: 7

element 6 before sort: 13

element 7 before sort: 20

element 8 before sort: 12

element 9 before sort: 21

element 10 before sort: 11

element 11 before sort: 22

element 12 before sort: 10

element 13 before sort: 23

element 14 before sort: 9

element 15 before sort: 24

element 16 before sort: 8

element 17 before sort: 25

element 18 before sort: 43

element 19 before sort: 62

element 20 before sort: 42

element 21 before sort: 63

element 22 before sort: 41

element 23 before sort: 18

element 24 before sort: 42

element 25 before sort: 17

element 26 before sort: 43

element 27 before sort: 16

element 28 before sort: 44

element 29 before sort: 15

element 30 before sort: 45

element 31 before sort: 14

element 32 before sort: 46

element 33 before sort: 79

element 34 before sort: 113

element 35 before sort: 78

element 36 before sort: 114

element 37 before sort: 77

element 38 before sort: 39

element 39 before sort: 78

element 40 before sort: 38

────────────────────────────────────────────────────────────────────────────────

element 1 after sort: 1

element 2 after sort: 2

element 3 after sort: 3

element 4 after sort: 6

element 5 after sort: 7

element 6 after sort: 8

element 7 after sort: 9

element 8 after sort: 10

element 9 after sort: 11

element 10 after sort: 12

element 11 after sort: 13

element 12 after sort: 14

element 13 after sort: 15

element 14 after sort: 16

element 15 after sort: 17

element 16 after sort: 18

element 17 after sort: 20

element 18 after sort: 21

element 19 after sort: 22

element 20 after sort: 23

element 21 after sort: 24

element 22 after sort: 25

element 23 after sort: 38

element 24 after sort: 39

element 25 after sort: 41

element 26 after sort: 42

element 27 after sort: 42

element 28 after sort: 43

element 29 after sort: 43

element 30 after sort: 44

element 31 after sort: 45

element 32 after sort: 46

element 33 after sort: 62

element 34 after sort: 63

element 35 after sort: 77

element 36 after sort: 78

element 37 after sort: 78

element 38 after sort: 79

element 39 after sort: 113

element 40 after sort: 114

────────────────────────────────────────────────────────────────────────────────

</pre>