Sorting algorithms/Gnome sort
You are encouraged to solve this task according to the task description, using any language you may know.
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:
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
| This page uses content from Wikipedia. The original article was at Gnome sort. The list of authors can be seen in the page history. As with Rosetta Code, the text of Wikipedia is available under the GNU FDL. (See links for details on variance) |
Gnome sort is a sorting algorithm which is similar to Insertion sort, except that moving an element to its proper place is accomplished by a series of swaps, as in Bubble Sort.
The pseudocode for the algorithm is:
function gnomeSort(a[0..size-1])
i := 1
j := 2
while i < size do
if a[i-1] <= a[i] then
// for descending sort, use >= for comparison
i := j
j := j + 1
else
swap a[i-1] and a[i]
i := i - 1
if i = 0 then
i := j
j := j + 1
endif
endif
done
Task: implement the Gnome sort in your language to sort an array (or list) of numbers.
ActionScript
<lang ActionScript>function gnomeSort(array:Array) { var pos:uint = 0; while(pos < array.length) { if(pos == 0 || array[pos] >= array[pos-1]) pos++; else { var tmp = array[pos]; array[pos] = array[pos-1]; array[pos-1] = tmp; pos--; } } return array; }</lang>
Ada
This example is a generic procedure for constrained array types. <lang Ada>generic
type Element_Type is private; type Index is (<>); type Collection is array(Index) of Element_Type; with function "<=" (Left, Right : Element_Type) return Boolean is <>;
procedure Gnome_Sort(Item : in out Collection);</lang>
<lang Ada>procedure Gnome_Sort(Item : in out Collection) is
procedure Swap(Left, Right : in out Element_Type) is
Temp : Element_Type := Left;
begin
Left := Right;
Right := Temp;
end Swap;
I : Integer := Index'Pos(Index'Succ(Index'First));
J : Integer := I + 1;
begin
while I <= Index'Pos(Index'Last) loop
if Item(Index'Val(I - 1)) <= Item(Index'Val(I)) then
I := J;
J := J + 1;
else
Swap(Item(Index'Val(I - 1)), Item(Index'Val(I)));
I := I - 1;
if I = Index'Pos(Index'First) then
I := J;
J := J + 1;
end if;
end if;
end loop;
end Gnome_Sort;</lang> Usage example: <lang Ada>with Gnome_Sort; with Ada.Text_Io; use Ada.Text_Io;
procedure Gnome_Sort_Test is
type Index is range 0..9; type Buf is array(Index) of Integer; procedure Sort is new Gnome_Sort(Integer, Index, Buf); A : Buf := (900, 700, 800, 600, 400, 500, 200, 100, 300, 0);
begin
for I in A'range loop
Put(Integer'Image(A(I)));
end loop;
New_Line;
Sort(A);
for I in A'range loop
Put(Integer'Image(A(I)));
end loop;
New_Line;
end Gnome_Sort_Test;</lang>
ALGOL 68
<lang algol68>MODE SORTSTRUCT = CHAR;
PROC inplace gnome sort = (REF[]SORTSTRUCT list)REF[]SORTSTRUCT: BEGIN
INT i:=LWB list + 1, j:=LWB list + 2;
WHILE i <= UPB list DO
IF list[i-1] <= list[i] THEN
i := j; j+:=1
ELSE
SORTSTRUCT swap = list[i-1]; list[i-1]:= list[i]; list[i]:= swap;
i-:=1;
IF i=LWB list THEN i:=j; j+:=1 FI
FI
OD;
list
END;
PROC gnome sort = ([]SORTSTRUCT seq)[]SORTSTRUCT:
in place gnome sort(LOC[LWB seq: UPB seq]SORTSTRUCT:=seq);
[]SORTSTRUCT char array data = "big fjords vex quick waltz nymph"; print((gnome sort(char array data), new line))</lang> Output:
abcdefghiijklmnopqrstuvwxyz
AutoHotkey
contributed by Laszlo on the ahk forum <lang AutoHotkey>MsgBox % GnomeSort("") MsgBox % GnomeSort("xxx") MsgBox % GnomeSort("3,2,1") MsgBox % GnomeSort("dog,000000,xx,cat,pile,abcde,1,cat,zz,xx,z")
GnomeSort(var) { ; SORT COMMA SEPARATED LIST
StringSplit a, var, `, ; make array, size = a0
i := 2, j := 3
While i <= a0 { ; stop when sorted
u := i-1
If (a%u% < a%i%) ; search for pairs to swap
i := j, j := j+1
Else { ; swap
t := a%u%, a%u% := a%i%, a%i% := t
If (--i = 1) ; restart search
i := j, j++
}
}
Loop % a0 ; construct string from sorted array
sorted .= "," . a%A_Index%
Return SubStr(sorted,2) ; drop leading comma
}</lang>
BASIC
<lang qbasic>dim a(0 to n-1) as integer '...more code... sort: i = 1 j = 2
while(i < ubound(a) - lbound(a))
if a(i-1) <= a(i) then
i = j
j = j + 1
else
swap a(i-1), a(i)
i = i - 1
if i = 0 then
i = j
j = j + 1
end if
end if
wend</lang>
BBC BASIC
<lang BBCBASIC>DEF PROC_GnomeSort1(Size%) I%=2 J%=2 REPEAT
IF data%(J%-1) <=data%(J%) THEN
I%+=1
J%=I%
ELSE
SWAP data%(J%-1),data%(J%)
J%-=1
IF J%=1 THEN
I%+=1
J%=I%
ENDIF
ENDIF
UNTIL I%>Size% ENDPROC</lang>
C
This algorithm sorts in place modifying the passed array (of n integer numbers).
<lang c>#define swap_(I,J) do { int t_; t_ = a[(I)]; \
a[(I)] = a[(J)]; a[(J)] = t_; } while(0)
void gnome_sort(int *a, int n) {
int i=1, j=2;
while(i < n) {
if ( a[i-1] <= a[i] ) {
i = j; j++;
} else {
swap_(i-1, i);
i--;
i = (i==0) ? j++ : i;
}
}
}
- undef swap_</lang>
C#
<lang csharp>public static void gnomeSort(ref int[] a) {
int i = 1; int j = 2;
while (i < a.Length)
{
if (a[i - 1] <= a[i])
{
i = j;
j++;
}
else
{
int tmp = a[i - 1];
a[i - 1] = a[i];
a[i--] = tmp;
i = (i == 0) ? j++ : i;
}
}
}
}</lang>
C++
Compiler: g++ (version 4.3.2 20081105 (Red Hat 4.3.2-7))
<lang cpp>#include <algorithm>
- include <iterator>
template<typename RandomAccessIterator> void gnomeSort(RandomAccessIterator begin, RandomAccessIterator end) {
RandomAccessIterator i = begin + 1; RandomAccessIterator j = begin + 2;
while(i < end) {
if(*(i - 1) <= *i) {
i = j;
++j;
} else {
std::iter_swap(i - 1, i);
--i;
if(i == begin) {
i = j;
++j;
}
}
}
}</lang>
Clojure
<lang clojure>(defn gnomesort
"pred is a sorting predicate (default: <=). It must be reflexive."
([c] (gnomesort <= c))
([pred c]
(if (empty? c)
c
(loop [vs nil, ws c]
(cond (empty? ws) (reverse vs)
(empty? vs) (recur (take 1 ws) (rest ws))
:else (let [[v & vr] vs, [w & wr] ws]
(if (pred v w)
(recur (cons w vs) wr)
(recur vr (cons w (cons v wr))))))))))
(println (gnomesort [3 1 4 1 5 9 2 6 5]))</lang>
COBOL
Procedure division stuff only. <lang COBOL> C-SORT SECTION.
C-000.
DISPLAY "SORT STARTING".
SET WB-IX-1 TO 2.
MOVE 1 TO WC-NEXT-POSN.
PERFORM E-GNOME UNTIL WC-NEXT-POSN > WC-SIZE.
DISPLAY "SORT FINISHED".
C-999.
EXIT.
E-GNOME SECTION.
E-000.
IF WB-ENTRY(WB-IX-1 - 1) NOT > WB-ENTRY(WB-IX-1)
ADD 1 TO WC-NEXT-POSN
SET WB-IX-1 TO WC-NEXT-POSN
ELSE
MOVE WB-ENTRY(WB-IX-1 - 1) TO WC-TEMP
MOVE WB-ENTRY(WB-IX-1) TO WB-ENTRY(WB-IX-1 - 1)
MOVE WC-TEMP TO WB-ENTRY(WB-IX-1)
SET WB-IX-1 DOWN BY 1
IF WB-IX-1 = 1
ADD 1 TO WC-NEXT-POSN
SET WB-IX-1 TO WC-NEXT-POSN.
E-999.
EXIT.</lang>
Common Lisp
<lang lisp>(defun gnome-sort (array predicate &aux (length (length array)))
(do ((position (min 1 length)))
((eql length position) array)
(cond
((eql 0 position)
(incf position))
((funcall predicate
(aref array position)
(aref array (1- position)))
(rotatef (aref array position)
(aref array (1- position)))
(decf position))
(t (incf position)))))</lang>
D
<lang d>import std.stdio: writeln; import std.algorithm: swap;
void gnomeSort(T)(T arr) {
int i = 1, j = 2;
while (i < arr.length) {
if (arr[i-1] <= arr[i]) {
i = j;
j++;
} else {
swap(arr[i-1], arr[i]);
i--;
if (i == 0) {
i = j;
j++;
}
}
}
}
void main() {
auto a = [3,4,2,5,1,6]; gnomeSort(a); writeln(a);
}</lang>
E
<lang e>def gnomeSort(array) {
var size := array.size()
var i := 1
var j := 2
while (i < size) {
if (array[i-1] <= array[i]) {
i := j
j += 1
} else {
def t := array[i-1]
array[i-1] := array[i]
array[i] := t
i -= 1
if (i <=> 0) {
i := j
j += 1
}
}
}
}</lang>
<lang e>? def a := [7,9,4,2,1,3,6,5,0,8].diverge()
- value: [7, 9, 4, 2, 1, 3, 6, 5, 0, 8].diverge()
? gnomeSort(a) ? a
- value: [0, 1, 2, 3, 4, 5, 6, 7, 8, 9].diverge()</lang>
Erlang
<lang Erlang>-module(gnome_sort). -export([gnome/1]).
gnome(L, []) -> L; gnome([Prev|P], [Next|N]) when Next > Prev -> gnome(P, [Next|[Prev|N]]); gnome(P, [Next|N]) -> gnome([Next|P], N). gnome([H|T]) -> gnome([H], T).</lang> <lang Erlang>Eshell V5.7.3 (abort with ^G) 1> c(gnome_sort). {ok,gnome_sort} 2> gnome_sort:gnome([8,3,9,1,3,2,6]). [1,2,3,3,6,8,9] 3> </lang>
F#
<lang fsharp>let inline gnomeSort (a: _ []) =
let rec loop i j =
if i < a.Length then
if a.[i-1] <= a.[i] then loop j (j+1) else
let t = a.[i-1]
a.[i-1] <- a.[i]
a.[i] <- t
if i=1 then loop j (j+1) else loop (i-1) j
loop 1 2</lang>
Forth
<lang forth>defer precedes defer exchange
- gnomesort ( a n)
swap >r 1 ( n c)
begin ( n c)
over over > ( n c f)
while ( n c)
dup if ( n c)
dup dup 1- over over r@ precedes
if r@ exchange 1- else drop drop 1+ then
else 1+ then ( n c)
repeat drop drop r> drop ( --)
create example
8 93 69 52 50 79 33 52 19 77 , , , , , , , , , ,
- noname >r cells r@ + @ swap cells r> + @ swap < ; is precedes
- noname >r cells r@ + swap cells r> + over @ over @ swap rot ! swap ! ; is exchange
- .array 10 0 do example i cells + ? loop cr ;
.array example 10 gnomesort .array</lang> A slightly optimized version is presented below, where Gnome sort keeps track of its previous position. This reduces the number of iterations significantly. <lang forth>: gnomesort+ ( a n)
swap >r 2 tuck 1- ( c2 n c1)
begin ( c2 n c1)
over over > ( c2 n c1 f)
while ( c2 n c1)
dup if ( c2 n c1)
dup dup 1- over over r@ precedes
if r@ exchange 1- else drop drop drop >r dup 1+ swap r> swap then
else drop >r dup 1+ swap r> swap then
repeat drop drop drop r> drop
- ( --)</lang>
Fortran
<lang fortran>program example
implicit none integer :: array(8) = (/ 2, 8, 6, 1, 3, 5, 4, 7 /)
call Gnomesort(array) write(*,*) array
contains
subroutine Gnomesort(a)
integer, intent(in out) :: a(:) integer :: i, j, temp
i = 2
j = 3
do while (i <= size(a))
if (a(i-1) <= a(i)) then
i = j
j = j + 1
else
temp = a(i-1)
a(i-1) = a(i)
a(i) = temp
i = i - 1
if (i == 1) then
i = j
j = j + 1
end if
end if
end do
end subroutine Gnomesort
end program example</lang>
Go
<lang go>package main
import "fmt"
var a = []int{170, 45, 75, -90, -802, 24, 2, 66}
func main() {
fmt.Println("before:", a)
gnomeSort()
fmt.Println("after: ", a)
}
func gnomeSort() {
for i, j := 1, 2; i < len(a); {
if a[i-1] > a[i] {
a[i-1], a[i] = a[i], a[i-1]
i--
if i > 0 {
continue
}
}
i = j
j++
}
}</lang>
Haskell
<lang haskell>gnomeSort [] = [] gnomeSort (x:xs) = gs [x] xs
where
gs vv@(v:vs) (w:ws) | v<=w = gs (w:vv) ws | otherwise = gs vs (w:v:ws) gs [] (y:ys) = gs [y] ys gs xs [] = reverse xs -- keeping the first argument of gs in reverse order avoids the deterioration into cubic behaviour </lang>
Io
Naive version: <lang io>List do(
gnomeSortInPlace := method(
idx := 1
while(idx <= size,
if(idx == 0 or at(idx) > at(idx - 1)) then(
idx = idx + 1
) else(
swapIndices(idx, idx - 1)
idx = idx - 1
)
)
self)
)
lst := list(5, -1, -4, 2, 9) lst gnomeSortInPlace println # ==> list(-4, -1, 2, 5, 9)</lang>
Optimized version, storing the position before traversing back towards the begining of the list (Wikipedia) <lang io>List do(
gnomeSortInPlace := method(
idx1 := 1
idx2 := 2
while(idx1 <= size,
if(idx1 == 0 or at(idx1) > at(idx1 - 1)) then(
idx1 = idx2
idx2 = idx2 + 1
) else(
swapIndices(idx1, idx1 - 1)
idx1 = idx1 - 1
)
)
self)
)
lst := list(5, -1, -4, 2, 9) lst gnomeSortInPlace println # ==> list(-4, -1, 2, 5, 9)</lang>
Icon and Unicon
<lang Icon>procedure main() #: demonstrate various ways to sort a list and string
demosort(gnomesort,[3, 14, 1, 5, 9, 2, 6, 3],"qwerty")
end
procedure gnomesort(X,op) #: return sorted list local i,j
op := sortop(op,X) # select how and what we sort
j := (i := 2) + 1 # translation of pseudo code
while i <= *X do {
if op(X[i],X[i-1]) then {
X[i] :=: X[i -:= 1]
if i > 1 then next
}
j := (i := j) + 1
}
return X
end</lang>
Note: This example relies on the supporting procedures 'sortop', and 'demosort' in Bubble Sort. The full demosort exercises the named sort of a list with op = "numeric", "string", ">>" (lexically gt, descending),">" (numerically gt, descending), a custom comparator, and also a string.
Abbreviated sample output:
Sorting Demo using procedure gnomesort
on list : [ 3 14 1 5 9 2 6 3 ]
with op = &null: [ 1 2 3 3 5 6 9 14 ] (0 ms)
...
on string : "qwerty"
with op = &null: "eqrtwy" (0 ms)
J
<lang J>position=: 0 {.@I.@, [ swap=: ] A.~ *@position * #@[ !@- <:@position gnome=: swap~ 2 >/\ ] gnomes=: gnome^:_</lang>
Note 1: this implementation of swap is actually rather silly, and will not work on long lists. A better implementation would be:<lang J>swap=: position (] {~ _1 0 + [)`(0 _1 + [)`]}^:(*@[) ]</lang>
Note 2: this implementation only works for domains where > is defined (in J, "greater than" only works on numbers). To work around this issue, you could define:<lang J>gt=: -.@(-: /:~)@,&< gnome=: swap~ 2 gt/\ ]</lang>
Note 3: this implementation does not return intermediate results. If you want them, you could use<lang J>gnomeps=: gnome^:a:</lang>
Note 4: gnomeps just shows intermediate results and does not show the gnome's position. You can extract the gnome's position using an expression such as<lang J>2 ~:/\ gnomeps</lang>.
Java
<lang java>public static void gnomeSort(int[] a) {
int i=1;
int j=2;
while(i < a.length) {
if ( a[i-1] <= a[i] ) {
i = j; j++;
} else {
int tmp = a[i-1];
a[i-1] = a[i];
a[i--] = tmp;
i = (i==0) ? j++ : i;
}
}
}</lang>
Lua
Keep in mind that Lua arrays initial index is 1. <lang lua>function gnomeSort(a)
local i, j = 2, 3
while i < #a do
if a[i-1] <= a[i] then
i = j
j = j + 1
else
a[i-1], a[i] = a[i], a[i-1] -- swap
i = i - 1
if i == 1 then -- 1 instead of 0
i = j
j = j + 1
end
end
end
end</lang> Example: <lang lua>list = { 5, 6, 1, 2, 9, 14, 2, 15, 6, 7, 8, 97 } gnomeSort(list) for i, j in pairs(list) do
print(j)
end</lang>
MATLAB
<lang MATLAB>function list = gnomeSort(list)
i = 2;
j = 3;
while i <= numel(list)
if list(i-1) <= list(i)
i = j;
j = j+1;
else
list([i-1 i]) = list([i i-1]); %Swap
i = i-1;
if i == 1
i = j;
j = j+1;
end
end %if
end %while
end %gnomeSort</lang>
Sample Usage: <lang MATLAB>>> gnomeSort([4 3 1 5 6 2])
ans =
1 2 3 4 5 6</lang>
Metafont
<lang metafont>def gnomesort(suffix v)(expr n) = begingroup save i, j, t;
i := 1; j := 2;
forever: exitif not (i < n);
if v[i-1] <= v[i]:
i := j; j := j + 1;
else:
t := v[i-1];
v[i-1] := v[i];
v[i] := t;
i := i - 1;
i := if i=0: j; j := j + 1 else: i fi;
fi
endfor
endgroup enddef;</lang>
<lang metafont>numeric a[]; for i = 0 upto 9: a[i] := uniformdeviate(40); message decimal a[i]; endfor message char10;
gnomesort(a, 10); for i = 0 upto 9: message decimal a[i]; endfor end</lang>
Objeck
<lang objeck> function : GnomeSort(a : Int[]) {
i := 1; j := 2;
while(i < a->Size()) {
if (a[i-1] <= a[i]) {
i := j;
j += 1;
}
else {
tmp := a[i-1];
a[i-1] := a[i];
a[i--] := tmp;
if(i = 0) {
i := j;
j += 1;
};
};
};
} </lang>
OCaml
from the toplevel: <lang ocaml># let gnome_sort a =
let i = ref 1
and j = ref 2 in
while !i < Array.length a do
if a.(!i-1) <= a.(!i) then
begin
i := !j;
j := !j + 1;
end else begin
swap a (!i-1) (!i);
i := !i - 1;
if !i = 0 then begin
i := !j;
j := !j + 1;
end;
end;
done;
;;
val gnome_sort : 'a array -> unit = <fun>
- let a = [| 7; 9; 4; 2; 1; 3; 6; 5; 0; 8; |] ;;
val a : int array = [|7; 9; 4; 2; 1; 3; 6; 5; 0; 8|]
- gnome_sort a ;;
- : unit = ()
- a ;;
- : int array = [|0; 1; 2; 3; 4; 5; 6; 7; 8; 9|]</lang>
Octave
<lang octave>function s = gnomesort(v)
i = 2; j = 3;
while ( i <= length(v) )
if ( v(i-1) <= v(i) )
i = j;
j++;
else
t = v(i-1);
v(i-1) = v(i);
v(i) = t;
i--;
if ( i == 1 )
i = j; j++;
endif endif endwhile s = v;
endfunction</lang>
<lang octave>v = [7, 9, 4, 2, 1, 3, 6, 5, 0, 8]; disp(gnomesort(v));</lang>
Oz
<lang oz>declare
fun {GnomeSort Xs}
case Xs of nil then nil
[] X|Xr then {Loop [X] Xr}
end
end
fun {Loop Vs Ws}
case [Vs Ws]
of [V|_ W|Wr] andthen V =< W then {Loop W|Vs Wr}
[] [V|Vr W|Wr] then {Loop Vr W|V|Wr}
[] [nil W|Wr] then {Loop [W] Wr}
[] [Vs nil ] then {Reverse Vs}
end
end
in
{Show {GnomeSort [3 1 4 1 5 9 2 6 5]}}</lang>
Pascal
<lang pascal>procedure gnomesort(var arr : Array of Integer; size : Integer); var
i, j, t : Integer;
begin
i := 1;
j := 2;
while i < size do begin
if arr[i-1] <= arr[i] then
begin
i := j; j := j + 1
end
else begin
t := arr[i-1]; arr[i-1] := arr[i]; arr[i] := t; i := i - 1; if i = 0 then begin i := j; j := j + 1 end
end end;
end;</lang>
Perl
<lang perl>use strict;
sub gnome_sort {
my @a = @_;
my $size = scalar(@a);
my $i = 1;
my $j = 2;
while($i < $size) {
if ( $a[$i-1] <= $a[$i] ) { $i = $j; $j++; } else { @a[$i, $i-1] = @a[$i-1, $i]; $i--; if ($i == 0) { $i = $j; $j++; } }
} return @a;
}</lang>
<lang perl>my @arr = ( 10, 9, 8, 5, 2, 1, 1, 0, 50, -2 ); print "$_\n" foreach gnome_sort( @arr );</lang>
Perl 6
<lang perl6>sub gnome_sort (@a is rw) {
my ($i, $j) = 1, 2;
while $i < @a {
if @a[$i - 1] <= @a[$i] {
($i, $j) = $j, $j + 1;
}
else {
(@a[$i - 1], @a[$i]) = @a[$i], @a[$i - 1];
--$i or ($i, $j) = $j, $j + 1;
}
}
}</lang>
PHP
<lang php>function gnomeSort($arr){ $i = 1; $j = 2; while($i < count($arr)){ if ($arr[$i-1] <= $arr[$i]){ $i = $j; $j++; }else{ list($arr[$i],$arr[$i-1]) = array($arr[$i-1],$arr[$i]); $i--; if($i == 0){ $i = $j; $j++; } } } return $arr; } $arr = array(3,1,6,2,9,4,7,8,5); echo implode(',',gnomeSort($arr));</lang>
1,2,3,4,5,6,7,8,9
PicoLisp
<lang PicoLisp>(de gnomeSort (Lst)
(let J (cdr Lst)
(for (I Lst (cdr I))
(if (>= (cadr I) (car I))
(setq I J J (cdr J))
(xchg I (cdr I))
(if (== I Lst)
(setq I J J (cdr J))
(setq I (prior I Lst)) ) ) ) )
Lst )</lang>
PowerBASIC
The BASIC example will work as-is if the array is declared in the same function as the sort. This example doesn't require that, but forces you to know your data type beforehand.
<lang powerbasic>SUB gnomeSort (a() AS LONG)
DIM i AS LONG, j AS LONG
i = 1
j = 2
WHILE (i < UBOUND(a) + 1)
IF (a(i - 1) <= a(i)) THEN
i = j
INCR j
ELSE
SWAP a(i - 1), a(i)
DECR i
IF 0 = i THEN
i = j
INCR j
END IF
END IF
WEND
END SUB
FUNCTION PBMAIN () AS LONG
DIM n(9) AS LONG, x AS LONG
RANDOMIZE TIMER
OPEN "output.txt" FOR OUTPUT AS 1
FOR x = 0 TO 9
n(x) = INT(RND * 9999)
PRINT #1, n(x); ",";
NEXT
PRINT #1,
gnomeSort n()
FOR x = 0 TO 9
PRINT #1, n(x); ",";
NEXT
CLOSE 1
END FUNCTION</lang>
Sample output:
7426 , 7887 , 8297 , 2671 , 7586 , 7160 , 1195 , 665 , 9352 , 6199 , 665 , 1195 , 2671 , 6199 , 7160 , 7426 , 7586 , 7887 , 8297 , 9352 ,
PureBasic
<lang PureBasic>Procedure GnomeSort(Array a(1))
Protected Size = ArraySize(a()) + 1
Protected i = 1, j = 2
While i < Size
If a(i - 1) <= a(i)
;for descending SORT, use >= for comparison
i = j
j + 1
Else
Swap a(i - 1), a(i)
i - 1
If i = 0
i = j
j + 1
EndIf
EndIf
Wend
EndProcedure</lang>
Python
<lang python>>>> def gnomesort(a): i,j,size = 1,2,len(a) while i < size: if a[i-1] <= a[i]: i,j = j, j+1 else: a[i-1],a[i] = a[i],a[i-1] i -= 1 if i == 0: i,j = j, j+1 return a
>>> gnomesort([3,4,2,5,1,6]) [1, 2, 3, 4, 5, 6] >>></lang>
R
<lang r>gnomesort <- function(x) {
i <- 1
j <- 1
while(i < length(x))
{
if(x[i] <= x[i+1])
{
i <- j
j <- j+1
} else
{
temp <- x[i]
x[i] <- x[i+1]
x[i+1] <- temp
i <- i - 1
if(i == 0)
{
i <- j
j <- j+1
}
}
}
x
} gnomesort(c(4, 65, 2, -31, 0, 99, 83, 782, 1)) # -31 0 1 2 4 65 83 99 782</lang>
REXX
<lang rexx> /*REXX program sorts an array using the gnome-sort method. */
call gen@ /*generate array elements. */ call show@ 'before sort' /*show before array elements*/ call gnomeSort highItem /*invoke the gnome sort. */ call show@ ' after sort' /*show after array elements*/ exit
/*─────────────────────────────────────gnomeSORT subroutine────────*/
gnomeSort: procedure expose @.; parse arg n
k=2
do j=3 while k<=n
km1=k-1
if @.km1<=@.k then k=j
else do
_=@.km1
@.km1=@.k
@.k=_
k=k-1
if k==1 then k=j
end
end
return
/*─────────────────────────────────────GEN@ subroutine─────────────*/
gen@: @.= /*assign default value. */
@.1='---the seven virtues---' @.2='=======================' @.3='Faith' @.4='Hope' @.5='Charity [Love]' @.6='Fortitude' @.7='Justice' @.8='Prudence' @.9='Temperance'
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:
element 1 before sort: ---the seven virtues--- element 2 before sort: ======================= element 3 before sort: Faith element 4 before sort: Hope element 5 before sort: Charity [Love] element 6 before sort: Fortitude element 7 before sort: Justice element 8 before sort: Prudence element 9 before sort: Temperance ──────────────────────────────────────────────────────────────────────────────── element 1 after sort: ---the seven virtues--- element 2 after sort: ======================= element 3 after sort: Charity [Love] element 4 after sort: Faith element 5 after sort: Hope element 6 after sort: Fortitude element 7 after sort: Justice element 8 after sort: Prudence element 9 after sort: Temperance ────────────────────────────────────────────────────────────────────────────────
Ruby
<lang ruby>class Array
def gnomesort!
i, j = 1, 2
while i < length
if self[i-1] <= self[i]
i, j = j, j+1
else
self[i-1], self[i] = self[i], self[i-1]
i -= 1
if i == 0
i, j = j, j+1
end
end
end
self
end
end ary = [7,6,5,9,8,4,3,1,2,0] ary.gnomesort!
- => [0, 1, 2, 3, 4, 5, 6, 7, 8, 9]</lang>
Smalltalk
<lang smalltalk>Smalltalk at: #gnomesort put: nil.
"Utility" OrderedCollection extend [
swap: a with: b [ |t|
t := self at: a.
self at: a put: b.
self at: b put: t
]
].
"Gnome sort as block closure" gnomesort := [ :c |
|i j|
i := 2. j := 3.
[ i <= (c size) ]
whileTrue: [
(c at: (i-1)) <= (c at: i)
ifTrue: [
i := j copy.
j := j + 1.
]
ifFalse: [
c swap: (i-1) with: i.
i := i - 1.
i == 1
ifTrue: [
i := j copy.
j := j + 1
]
]
]
].</lang>
Testing
<lang smalltalk>|r o| r := Random new. o := OrderedCollection new.
1 to: 10 do: [ :i | o add: (r between: 0 and: 50) ].
gnomesort value: o.
1 to: 10 do: [ :i | (o at: i) displayNl ].</lang>
Tcl
<lang tcl>package require Tcl 8.5 package require struct::list
proc gnomesort {a} {
set i 1
set j 2
set size [llength $a]
while {$i < $size} {
if {[lindex $a [expr {$i - 1}]] <= [lindex $a $i]} {
set i $j
incr j
} else {
struct::list swap a [expr {$i - 1}] $i
incr i -1
if {$i == 0} {
set i $j
incr j
}
}
}
return $a
}
puts [gnomesort {8 6 4 2 1 3 5 7 9}] ;# => 1 2 3 4 5 6 7 8 9</lang>
TI-83 BASIC
Store input into L1, run prgmSORTGNOM, output will be in L2.
:1→P :L1→L2 :While P<dim(L2) :If PP=1 :Then :P+1→P :Else :If L2(P)≥L2(P-1) :Then :P+1→P :Else :L2(P)→Q :L2(P-1)→L2(P) :Q→L2(P-1) :P-1→P :End :End :End :If L2(dim(L2))<L2(dim(L2)-1) :Then :L2(dim(L2))→Q :L2(dim(L2)-1)→L2(dim(L2)) :Q→L2(dim(L2)-1) :End :DelVar P :DelVar Q :Return
VBScript
Implementation
<lang vb>function gnomeSort( a ) dim i dim j i = 1 j = 2 do while i < ubound( a ) + 1 if a(i-1) <= a(i) then i = j j = j + 1 else swap a(i-1), a(i) i = i - 1 if i = 0 then i = j j = j + 1 end if end if loop gnomeSort = a end function
sub swap( byref x, byref y ) dim temp temp = x x = y y = temp end sub</lang>
Invocation
<lang vb>dim a dim b
a = array( "zanzibar", "aardvark","ampicillin","zulu","gogodala", "wolverhampton") b = gnomeSort( a ) wscript.echo join(a, ", ")
a = array( 234,567,345,568,2345,89,547,23,649,5769,456,456,567) b = gnomeSort( a ) wscript.echo join(a, ", ")
a = array( true, false, true, true, false, false, true, false) b = gnomeSort( a ) wscript.echo join(a, ", ")
a = array( 1,2,2,4,67789,-3,-45.99) b = gnomeSort( a ) wscript.echo join(a, ", ")
a = array( now(), now()-1,now()+2) b = gnomeSort( a ) wscript.echo join(a, ", ")</lang>
Output
<lang VBScript>aardvark, ampicillin, gogodala, wolverhampton, zanzibar, zulu 23, 89, 234, 345, 456, 456, 547, 567, 567, 568, 649, 2345, 5769 True, True, True, True, False, False, False, False -45.99, -3, 1, 2, 2, 4, 67789 2/02/2010 10:19:51 AM, 3/02/2010 10:19:51 AM, 5/02/2010 10:19:51 AM</lang> Note: All data in VBScript is of type Variant. Thus the code can sort many different types of data without code modification.
Ursala
The function is parameterized by a relational predicate and operates on a list. The algorithm is to scan forward until finding an item out of order, bubble it backwards to its proper position and resume scanning forward from where it was. <lang Ursala>gnome_sort "p" =
@NiX ^=lx -+ # iteration
~&r?\~& @lNXrX ->llx2rhPlrPCTxPrtPX~&lltPlhPrCXPrX ~&ll&& @llPrXh not "p", # backward bubble ->~&rhPlCrtPX ~&r&& ~&lZ!| @bh "p"+- # forward scan</lang>
Most of the code is wasted on dull but unavoidable stack manipulations. Here is a test program using the lexical partial order relation. <lang Ursala>#import std
- cast %s
t = gnome_sort(lleq) 'dfijhkwlawfkjnksdjnoqwjefgflkdsgioi'</lang> output:
'adddeffffgghiiijjjjkkkkllnnooqsswww'
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