Common list elements: Difference between revisions

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{{Template:Strings}}
<br><br>
 
=={{header|11l}}==
<syntaxhighlight lang="11l">F cle(nums)
V r = Set(nums[0])
L(num) nums[1..]
r = r.intersection(Set(num))
R r
 
print(cle([[2, 5, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 9, 8, 4], [1, 3, 7, 6, 9]]))</syntaxhighlight>
 
{{out}}
<pre>
Set([3, 6, 9])
</pre>
 
=={{header|Action!}}==
{{libheader|Action! Tool Kit}}
<syntaxhighlight lang="action!">INCLUDE "D2:SORT.ACT" ;from the Action! Tool Kit
 
DEFINE PTR="CARD"
 
PROC PrintArray(BYTE ARRAY a BYTE len)
BYTE i
 
Print(" [")
IF len>0 THEN
FOR i=0 TO len-1
DO
PrintB(a(i))
IF i<len-1 THEN Put(' ) FI
OD
FI
PrintE("]")
RETURN
 
BYTE FUNC Contains(BYTE ARRAY a BYTE len,value)
BYTE i,count
 
count=0
IF len>0 THEN
FOR i=0 TO len-1
DO
IF a(i)=value THEN count==+1 FI
OD
FI
RETURN (count)
 
PROC CommonListElements(PTR ARRAY arrays
BYTE ARRAY lengths BYTE count
BYTE ARRAY res BYTE POINTER resLen)
BYTE ARRAY a
BYTE i,j,len,value,cnt,maxcnt
 
resLen^=0
IF count=0 THEN RETURN FI
FOR i=0 TO count-1
DO
IF lengths(i)=0 THEN RETURN FI
OD
 
a=arrays(0) len=lengths(0)
IF count=1 THEN
MoveBlock(res,a,len) RETURN
FI
 
FOR i=0 TO len-1
DO
value=a(i)
IF Contains(res,resLen^,value)=0 THEN
maxcnt=Contains(a,len,value)
FOR j=1 TO count-1
DO
cnt=Contains(arrays(j),lengths(j),value)
IF cnt<maxcnt THEN maxcnt=cnt FI
OD
IF maxcnt>0 THEN
FOR j=1 TO maxcnt
DO
res(resLen^)=value resLen^==+1
OD
FI
FI
OD
SortB(res,resLen^,0)
RETURN
 
PROC Test(PTR ARRAY arrays BYTE ARRAY lengths BYTE count)
BYTE ARRAY res(100)
BYTE len,i
 
CommonListElements(arrays,lengths,count,res,@len)
PrintE("Input:")
FOR i=0 TO count-1
DO
PrintArray(arrays(i),lengths(i))
OD
PrintE("Intersection:")
PrintArray(res,len) PutE()
RETURN
 
PROC Main()
PTR ARRAY arrays(3)
BYTE ARRAY
lengths(3)=[8 7 5],
a1(8)=[2 5 1 3 8 9 4 6],
a2(7)=[3 5 6 2 9 8 4],
a3(5)=[1 3 7 6 9],
a4(8)=[2 2 1 3 8 9 4 6],
a5(7)=[3 5 6 2 2 2 4],
a6(5)=[2 3 7 6 2],
a7(5)=[0 1 7 8 9]
BYTE len
 
Put(125) PutE() ;clear the screen
arrays(0)=a1 arrays(1)=a2 arrays(2)=a3
Test(arrays,lengths,3)
arrays(0)=a4 arrays(1)=a5 arrays(2)=a6
Test(arrays,lengths,3)
arrays(2)=a7
Test(arrays,lengths,3)
RETURN</syntaxhighlight>
{{out}}
[https://gitlab.com/amarok8bit/action-rosetta-code/-/raw/master/images/Common_list_elements.png Screenshot from Atari 8-bit computer]
<pre>
Input:
[2 5 1 3 8 9 4 6]
[3 5 6 2 9 8 4]
[1 3 7 6 9]
Intersection:
[3 6 9]
 
Input:
[2 2 1 3 8 9 4 6]
[3 5 6 2 2 2 4]
[2 3 7 6 2]
Intersection:
[2 2 3 6]
 
Input:
[2 2 1 3 8 9 4 6]
[3 5 6 2 2 2 4]
[0 1 7 8 9]
Intersection:
[]
</pre>
 
=={{header|Ada}}==
<langsyntaxhighlight Adalang="ada">with Ada.Text_Io;
with Ada.Containers.Vectors;
 
Line 53 ⟶ 202:
R := Common_Elements (R, C);
Put (R);
end Common;</langsyntaxhighlight>
{{out}}
<pre>[ 3 9 6 ]</pre>
 
=={{header|ALGOL 68}}==
<syntaxhighlight lang="algol68">
BEGIN # find common elements of lists #
 
PRIO COMMON = 1;
# returns the common elements of a and b #
OP COMMON = ( []INT a, b )[]INT:
IF INT a len = ( UPB a - LWB a ) + 1;
INT b len = ( UPB b - LWB b ) + 1;
a len < 1 OR b len < 1
THEN # one or both lists is/are empty #
[]INT()
ELIF a len < b len
THEN # both lists are non-empty, b is shorter #
b COMMON a
ELSE # both lists are non-empty, a is at most as long as b #
[ 1 : b len ]INT result;
[ LWB a : UPB a ]BOOL used;
FOR i FROM LWB a TO UPB a DO used[ i ] := FALSE OD;
INT r pos := 0;
FOR b pos FROM LWB b TO UPB b DO
BOOL found := FALSE;
FOR a pos FROM LWB a TO UPB a WHILE NOT found DO
IF NOT used[ a pos ] THEN
IF ( found := a[ a pos ] = b[ b pos ] ) THEN
result[ r pos +:= 1 ] := b[ b pos ];
used[ a pos ] := TRUE
FI
FI
OD
OD;
result[ : r pos ]
FI # COMMON # ;
# returns the common elements in the lists in nums #
OP COMMON = ( [][]INT nums )[]INT:
IF 1 UPB nums < 1 LWB nums THEN # no lists #
[]INT()
ELIF 1 UPB nums = 1 LWB nums THEN # only one list #
nums[ LWB nums ]
ELSE # two or more lists #
FLEX[ 1 : 0 ]INT result;
result := nums[ LWB nums ] COMMON nums[ LWB nums + 1 ];
FOR i FROM LWB nums + 2 TO UPB nums DO
result := result COMMON nums[ i ]
OD;
result
FI # COMMON # ;
 
print( ( COMMON [][]INT( ( 2, 5, 1, 3, 8, 9, 4, 6 )
, ( 3, 5, 6, 2, 9, 8, 4 )
, ( 1, 3, 7, 6, 9 )
)
)
)
END
</syntaxhighlight>
{{out}}
<pre>
+3 +6 +9
</pre>
 
=={{header|APL}}==
APL has the built-in intersection function <code>∩</code>
 
<langsyntaxhighlight APLlang="apl"> ∩/ (2 5 1 3 8 9 4 6) (3 5 6 2 9 8 4) (1 3 7 9 6)
3 9 6 </langsyntaxhighlight>
 
=={{header|AppleScript}}==
===AppleScriptObjC===
<langsyntaxhighlight lang="applescript">use AppleScript version "2.4" -- OS X 10.10 (Yosemite) or later
use framework "Foundation"
use sorter : script "Insertion Sort" -- <https://www.rosettacode.org/wiki/Sorting_algorithms/Insertion_sort#AppleScript>
Line 80 ⟶ 290:
set commonElements to commonListElements({{2, 5, 1, 3, 8, 9, 4, 6}, {3, 5, 6, 2, 9, 8, 4}, {1, 3, 7, 6, 9}})
tell sorter to sort(commonElements, 1, -1)
return commonElements</langsyntaxhighlight>
 
{{output}}
<syntaxhighlight lang ="applescript">{3, 6, 9}</langsyntaxhighlight>
 
===Core language only===
The requirement for AppleScript 2.3.1 is only for the 'use' command which loads the "Insertion Sort" script. If the sort's instead loaded with the older 'load script' command or copied into the code, this will work on systems as far back as Mac OS X 10.5 (Leopard) or earlier. Same output as above.
<langsyntaxhighlight lang="applescript">use AppleScript version "2.3.1" -- Mac OS X 10.9 (Mavericks) or later.
use sorter : script "Insertion Sort" -- <https://www.rosettacode.org/wiki/Sorting_algorithms/Insertion_sort#AppleScript>
 
Line 113 ⟶ 323:
set commonElements to commonListElements({{2, 5, 1, 3, 8, 9, 4, 6}, {3, 5, 6, 2, 9, 8, 4}, {1, 3, 7, 6, 9}})
tell sorter to sort(commonElements, 1, -1)
return commonElements</langsyntaxhighlight>
 
=={{header|Arturo}}==
 
<syntaxhighlight lang="rebol">commonElements: function [subsets][
if zero? size subsets -> return []
if 1 = size subsets -> return first subsets
 
result: first subsets
 
loop slice subsets 1 dec size subsets 'subset [
result: intersection result subset
]
return result
]
 
print commonElements [
[2 5 1 3 8 9 4 6]
[3 5 6 2 9 8 4]
[1 3 7 6 9]
]</syntaxhighlight>
 
{{out}}
 
<pre>3 6 9</pre>
 
=={{header|AutoHotkey}}==
<langsyntaxhighlight AutoHotkeylang="autohotkey">Common_list_elements(nums){
counter := [], output := []
for i, num in nums
Line 124 ⟶ 358:
return output
}
</syntaxhighlight>
</lang>
Examples:<langsyntaxhighlight AutoHotkeylang="autohotkey">nums := [[2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9]]
output := Common_list_elements(nums)
return</langsyntaxhighlight>
{{out}}
<pre>[3, 6, 9]</pre>
 
=={{header|AWK}}==
<syntaxhighlight lang="awk">
<lang AWK>
# syntax: GAWK -f COMMON_LIST_ELEMENTS.AWK
BEGIN {
Line 154 ⟶ 388:
exit(0)
}
</syntaxhighlight>
</lang>
{{out}}
<pre>
[2,5,1,3,8,9,4,6],[3,5,6,2,9,8,4],[1,3,7,6,9] : 3 6 9
</pre>
 
=={{header|BQN}}==
<syntaxhighlight lang="bqn">(∊/⊣)´ ⟨2,5,1,3,8,9,4,6⟩‿⟨3,5,6,2,9,8,4⟩‿⟨1,3,7,6,9⟩</syntaxhighlight>
{{out}}
<pre>⟨ 3 9 6 ⟩</pre>
 
=={{header|CLU}}==
<syntaxhighlight lang="clu">contains = proc [T: type] (a: array[T], v: T) returns (bool)
where T has equal: proctype (T,T) returns (bool)
for i: T in array[T]$elements(a) do
if i=v then return(true) end
end
return(false)
end contains
 
common = proc [T: type] (lists: ssT) returns (sT)
where T has equal: proctype (T,T) returns (bool)
sT = sequence[T]
aT = array[T]
ssT = sequence[sequence[T]]
cur: aT := sT$s2a(ssT$bottom(lists))
for i: int in int$from_to(2, ssT$size(lists)) do
next: aT := aT$[]
for e: T in sT$elements(lists[i]) do
if contains[T](cur, e) then
aT$addh(next,e)
end
end
cur := next
end
return(sT$a2s(cur))
end common
 
start_up = proc ()
si = sequence[int]
ssi = sequence[sequence[int]]
nums: ssi := ssi$[
si$[2,5,1,3,8,9,4,6],
si$[3,5,6,2,9,8,4],
si$[1,3,7,6,9]
]
po: stream := stream$primary_output()
for i: int in si$elements(common[int](nums)) do
stream$puts(po, int$unparse(i) || " ")
end
end start_up</syntaxhighlight>
{{out}}
<pre>3 6 9</pre>
 
=={{header|Excel}}==
===LAMBDA===
Line 167 ⟶ 453:
 
{{Works with|Office 365 Betas 2021}}
<langsyntaxhighlight lang="lisp">INTERSECT
=LAMBDA(xs,
LAMBDA(ys,
Line 191 ⟶ 477:
xs
)
)</langsyntaxhighlight>
 
and also assuming the following generic bindings in Name Manager:
<langsyntaxhighlight lang="lisp">ELEM
=LAMBDA(x,
LAMBDA(xs,
Line 234 ⟶ 520:
)
)
)</langsyntaxhighlight>
 
{{Out}}
Line 322 ⟶ 608:
|
|}
 
=={{header|Delphi}}==
{{works with|Delphi|6.0}}
{{libheader|SysUtils,StdCtrls}}
 
 
<syntaxhighlight lang="Delphi">
const Set1: set of byte = [2,5,1,3,8,9,4,6];
const Set2: set of byte = [3,5,6,2,9,8,4];
const Set3: set of byte = [1,3,7,6,9];
 
 
procedure CommonListElements(Memo: TMemo);
{Using Delphi "sets" to find common elements}
var I,Start,Stop: integer;
var Common: set of byte;
var S: string;
begin
{Uses "*" intersection set operator to}
{ find items common to all three sets}
Common:=Set1 * Set2 * Set3;
Memo.Lines.Add('Common Elements in');
Memo.Lines.Add(' [2,5,1,3,8,9,4,6]');
Memo.Lines.Add(' [3,5,6,2,9,8,4]');
Memo.Lines.Add(' [1,3,7,6,9]: ');
S:='';
{Display the common items}
for I:=0 to 9 do
if I in Common then S:=S+IntToStr(I)+',';
Memo.Lines.Add(S);
end;
 
</syntaxhighlight>
{{out}}
<pre>
Common Elements in
[2,5,1,3,8,9,4,6]
[3,5,6,2,9,8,4]
[1,3,7,6,9]:
3,6,9,
Elapsed Time: 5.260 ms.
</pre>
 
 
=={{header|EasyLang}}==
<syntaxhighlight>
nums[][] = [ [ 2 5 1 3 8 9 4 6 ] [ 3 5 6 2 9 8 4 ] [ 1 3 7 6 9 ] ]
#
found = 1
for e in nums[1][]
for l = 2 to len nums[][]
found = 0
for x in nums[l][]
if e = x
found = 1
break 1
.
.
if found = 0
break 1
.
.
if found = 1
r[] &= e
.
.
print r[]
</syntaxhighlight>
 
=={{header|F_Sharp|F#}}==
Of course it is possible to use sets but I thought the idea was not to?
<langsyntaxhighlight lang="fsharp">
// Common list elements. Nigel Galloway: February 25th., 2021
let nums=[|[2;5;1;3;8;9;4;6];[3;5;6;2;9;8;4];[1;3;7;6;9]|]
printfn "%A" (nums|>Array.reduce(fun n g->n@g)|>List.distinct|>List.filter(fun n->nums|>Array.forall(fun g->List.contains n g)));;
</syntaxhighlight>
</lang>
{{out}}
<pre>
Line 338 ⟶ 692:
Note: in older versions of Factor, <code>intersect-all</code> was called <code>intersection</code>.
{{works with|Factor|0.99 2021-02-05}}
<langsyntaxhighlight lang="factor">USING: prettyprint sets ;
 
{ { 2 5 1 3 8 9 4 6 } { 3 5 6 2 9 8 4 } { 1 3 7 6 9 } } intersect-all .</langsyntaxhighlight>
{{out}}
<pre>
{ 3 6 9 }
</pre>
 
=={{header|FreeBASIC}}==
<syntaxhighlight lang="freebasic">dim as integer nums(1 to 3, 1 to 8) = {{2,5,1,3,8,9,4,6}, {3,5,6,2,9,8,4}, {1,3,7,6,9} }
redim as integer outp(0)
dim as integer i, j
dim as boolean found
 
function is_in( s() as integer, n as integer, r as integer ) as boolean
for i as uinteger = 1 to ubound(s,2)
if s(r,i)=n then return true
next i
return false
end function
 
for i = 1 to 8
found = true
for j = 2 to 3
if not is_in( nums(), nums(1,i), j ) then found = false
next j
if found then
redim preserve as integer outp(1 to 1+ubound(outp))
outp(ubound(outp)) = nums(1,i)
end if
next i
 
for i = 1 to ubound(outp)
print outp(i);" ";
next i</syntaxhighlight>
{{out}}<pre>3 9 6</pre>
 
=={{header|Go}}==
{{trans|Wren}}
<langsyntaxhighlight lang="go">package main
 
import "fmt"
Line 409 ⟶ 792:
fmt.Println()
}
}</langsyntaxhighlight>
 
{{out}}
Line 419 ⟶ 802:
[3 6 2 2]
</pre>
 
=={{header|Haskell}}==
<langsyntaxhighlight Haskelllang="haskell">import qualified Data.Set as Set
 
task :: Ord a => [[a]] -> [a]
Line 426 ⟶ 810:
task xs = Set.toAscList . foldl1 Set.intersection . map Set.fromList $ xs
 
main = print $ task [[2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9]]</langsyntaxhighlight>
{{out}}
<pre>[3,6,9]</pre>
 
=={{header|J}}==
 
<syntaxhighlight lang="j"> 2 5 1 3 8 9 4 6([-.-.)3 5 6 2 9 8 4([-.-.)1 3 7 6 9
3 9 6</syntaxhighlight>
 
Or,
 
<syntaxhighlight lang="j"> ;([-.-.)&.>/2 5 1 3 8 9 4 6;3 5 6 2 9 8 4;1 3 7 6 9
3 9 6</syntaxhighlight>
 
=={{header|jq}}==
Line 437 ⟶ 831:
on the arrays whose intersection is sought. The helper function, `ios`,
might be independently useful and so is defined as a top-level filter.
<langsyntaxhighlight lang="jq"># If a and b are sorted lists, and if all the elements respectively of a and b are distinct,
# then [a,b] | ios will emit the stream of elements in the set-intersection of a and b.
def ios:
Line 457 ⟶ 851:
elif any(.[]; length == 0) then []
else sort_by(length) | go
end;</langsyntaxhighlight>
<langsyntaxhighlight lang="jq"># The task:
[[2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9]]</langsyntaxhighlight>
{{out}}
<pre>
Line 465 ⟶ 859:
</pre>
 
=={{header|K}}==
{{works with|ngn/k}}<syntaxhighlight lang=K>{x^x^y}/(2 5 1 3 8 9 4 6;1 3 7 6 9;3 5 6 2 9 8 4)
3 9 6</syntaxhighlight>
 
=={{header|Ksh}}==
<syntaxhighlight lang="ksh">
#!/bin/ksh
 
# Find the common list elements in an integer array nums[][]
 
# # Variables:
#
typeset -a nums=( (2 5 1 3 8 9 4 6) (3 5 6 2 9 8 4) (1 3 7 6 9) )
 
# # Functions:
#
 
# # Function _flatten(arr[][] arr[]) - flatten input matrix
#
function _flatten {
typeset _inarr ; nameref _inarr="$1"
typeset _outarr ; nameref _outarr="$2"
typeset _i ; integer _i
 
_oldIFS=$IFS ; IFS=\|
for ((_i=1; _i<${#_inarr[*]}; _i++)); do
_outarr[_i]=${_inarr[_i][*]}
done
IFS=$oldIFS
}
 
######
# main #
######
 
typeset -a flatarr output
 
_flatten nums flatarr
 
integer i j
for ((i=0; i<${#nums[0][*]}; i++)); do
integer cnt=0
for ((j=1; j<=${#flatarr[*]}; j++)); do
[[ ${nums[0][i]} == @(${flatarr[j]%\|}) ]] && (( cnt++ ))
done
(( cnt == 2 )) && output+=( ${nums[0][i]} )
done
 
print "( ${output[@]} )"</syntaxhighlight>
{{out}}
<pre>( 3 9 6 )</pre>
 
=={{header|Julia}}==
<langsyntaxhighlight lang="julia">
julia> intersect([2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9])
3-element Array{Int64,1}:
Line 473 ⟶ 918:
9
6
</syntaxhighlight>
</lang>
 
=={{header|Lambdatalk}}==
<syntaxhighlight lang="scheme">
{def intersection
{def intersection.r
{lambda {:a :b :c :d}
{if {A.empty? :a}
then :d
else {intersection.r {A.rest :a} :b :c
{if {and {> {A.in? {A.first :a} :b} -1}
{> {A.in? {A.first :a} :c} -1}}
then {A.addlast! {A.first :a} :d}
else :d} }}}}
 
{lambda {:a :b :c}
{A.sort! < {intersection.r :a :b :c {A.new}}} }}
-> intersection
 
{intersection
{A.new 2 5 1 3 8 9 4 6}
{A.new 3 5 6 2 9 8 4}
{A.new 1 3 7 6 9}
}
-> [3,6,9]
</syntaxhighlight>
 
=={{header|Mathematica}}/{{header|Wolfram Language}}==
<syntaxhighlight lang="mathematica">Intersection[{2, 5, 1, 3, 8, 9, 4, 6}, {3, 5, 6, 2, 9, 8, 4}, {1, 3, 7, 6, 9}]</syntaxhighlight>
{{out}}
<pre>{3, 6, 9}</pre>
 
=={{header|Maxima}}==
<syntaxhighlight lang="maxima">
common_elems(lst):=block(map(setify,lst),apply(intersection,%%),listify(%%))$
nums:[[2,5,1,3,8,9,4,6],[3,5,6,2,9,8,4],[1,3,7,6,9]]$
common_elems(nums);
</syntaxhighlight>
{{out}}
<pre>
[3,6,9]
</pre>
 
=={{header|Nim}}==
<langsyntaxhighlight Nimlang="nim">import algorithm, sequtils
 
proc commonElements(list: openArray[seq[int]]): seq[int] =
Line 487 ⟶ 974:
result.add val
 
echo commonElements([@[2,5,1,3,8,9,4,6], @[3,5,6,2,9,8,4], @[1,3,7,6,9]])</langsyntaxhighlight>
 
{{out}}
Line 493 ⟶ 980:
 
=={{header|Perl}}==
<langsyntaxhighlight lang="perl">@nums = ([2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9]);
map { print "$_ " if @nums == ++$c{$_} } @$_ for @nums;</langsyntaxhighlight>
{{out}}
<pre>3 6 9</pre>
 
=={{header|Phix}}==
<!--<langsyntaxhighlight Phixlang="phix">(phixonline)-->
<span style="color: #008080;">function</span> <span style="color: #000000;">intersection</span><span style="color: #0000FF;">(</span><span style="color: #004080;">sequence</span> <span style="color: #000000;">s</span><span style="color: #0000FF;">)</span>
<span style="color: #004080;">sequence</span> <span style="color: #000000;">res</span> <span style="color: #0000FF;">=</span> <span style="color: #0000FF;">{}</span>
Line 519 ⟶ 1,006:
<span style="color: #0000FF;">?</span><span style="color: #000000;">intersection</span><span style="color: #0000FF;">({{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">8</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">,</span><span style="color: #000000;">8</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">7</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">}})</span>
<span style="color: #0000FF;">?</span><span style="color: #000000;">intersection</span><span style="color: #0000FF;">({{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">1</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">8</span><span style="color: #0000FF;">,</span><span style="color: #000000;">9</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">5</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">4</span><span style="color: #0000FF;">},{</span><span style="color: #000000;">2</span><span style="color: #0000FF;">,</span><span style="color: #000000;">3</span><span style="color: #0000FF;">,</span><span style="color: #000000;">7</span><span style="color: #0000FF;">,</span><span style="color: #000000;">6</span><span style="color: #0000FF;">,</span><span style="color: #000000;">2</span><span style="color: #0000FF;">}})</span>
<!--</langsyntaxhighlight>-->
Note that a (slightly more flexible) intersection() function is also defined in sets.e, so you could just include that instead, and use it the same way.
{{out}}
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===Without Duplicates===
<langsyntaxhighlight lang="python">"""Find distinct common list elements using set.intersection."""
 
def common_list_elements(*lists):
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result = common_list_elements(*case)
print(f"Intersection of {case} is {result}")
</syntaxhighlight>
</lang>
 
{{out}}
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===With Duplicates===
<langsyntaxhighlight lang="python">"""Find common list elements using collections.Counter (multiset)."""
 
from collections import Counter
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result = common_list_elements(*case)
print(f"Intersection of {case} is {result}")
</syntaxhighlight>
</lang>
 
{{out}}
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=={{header|Quackery}}==
 
<langsyntaxhighlight Quackerylang="quackery"> [ behead sort swap witheach
[ sort [] temp put
[ over [] !=
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2drop temp take ] ] is common ( [ [ --> [ )
 
' [ [ 2 5 1 3 8 9 4 6 ] [ 3 5 6 2 9 8 4 ] [ 1 3 7 6 9 ] ] common echo</langsyntaxhighlight>
 
{{out}}
Line 607 ⟶ 1,094:
 
=={{header|Raku}}==
<syntaxhighlight lang="raku" perl6line>put [∩] [2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9,3];</langsyntaxhighlight>
{{out}}
<pre>6 9 3</pre>
Line 613 ⟶ 1,100:
=={{header|REXX}}==
This REXX version properly handles the case of duplicate entries in a list &nbsp; (which shouldn't happen in a true list).
<langsyntaxhighlight lang="rexx">/*REXX program finds and displays the common list elements from a collection of sets. */
parse arg a /*obtain optional arguments from the CL*/
if a='' | a="," then a= '[2,5,1,3,8,9,4,6] [3,5,6,2,9,8,4] [1,3,7,6,9]' /*defaults.*/
Line 630 ⟶ 1,117:
end /*k*/
/*stick a fork in it, we're all done. */
say 'the list of common elements in all sets: ' "["translate(space($), ',', " ")']'</langsyntaxhighlight>
{{out|output|text=&nbsp; when using the default inputs:}}
<pre>
Line 637 ⟶ 1,124:
 
=={{header|Ring}}==
<langsyntaxhighlight lang="ring">
nums = [[2,5,1,3,8,9,4,6],[3,5,6,2,9,8,4],[1,3,7,6,9]]
sumNums = []
Line 690 ⟶ 1,177:
txt = txt + "]"
see txt
</syntaxhighlight>
</lang>
{{out}}
<pre>
common list elements are: [3,6,9]
</pre>
 
=={{header|RPL}}==
Can handle duplicates.
{{works with|HP|48}}
« SWAP LIST→ → n
« 'n' DECR DUP 3 + ROLL - 2 +
ROLL DROP n →LIST
» » '<span style="color:blue">POPL</span>' STO <span style="color:grey">@ ''( {list} idx_item_to_remove → {list} )''</span>
« '''IF''' OVER SIZE OVER SIZE < '''THEN''' SWAP '''END'''
0 → a j
« { } SWAP
'''WHILE''' 'j' INCR a SIZE ≤ '''REPEAT'''
a j GET
'''IF''' DUP2 POS '''THEN'''
LASTARG ROT SWAP <span style="color:blue">POPL</span>
ROT ROT + SWAP
'''ELSE''' DROP '''END'''
'''END''' DROP
» » '<span style="color:blue">INTER</span>' STO
 
{ 2 5 1 3 8 9 4 6 } { 3 5 6 2 9 8 4 } { 1 3 7 6 9 } <span style="color:blue">INTER</span> <span style="color:blue">INTER</span>
{ 2 2 1 3 8 9 4 6 } { 3 5 6 2 2 2 4 } { 2 3 7 6 2 } <span style="color:blue">INTER</span> <span style="color:blue">INTER</span>
{{out}}
<pre>
2: { 3 6 9 }
1: { 3 6 2 2 }
</pre>
 
=={{header|Ruby}}==
<syntaxhighlight lang="ruby">nums = [2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9]
p nums.inject(&:intersection) # or nums.inject(:&)
</syntaxhighlight>
{{out}}
<pre>[3, 9, 6]
</pre>
 
=={{header|V (Vlang)}}==
{{trans|go}}
<syntaxhighlight lang="v (vlang)">fn index_of(l []int, n int) int {
for i in 0..l.len {
if l[i] == n {
return i
}
}
return -1
}
fn common2(l1 []int, l2 []int) []int {
// minimize number of lookups
c1, c2 := l1.len, l2.len
mut shortest, mut longest := l1.clone(), l2.clone()
if c1 > c2 {
shortest, longest = l2.clone(), l1.clone()
}
mut longest2 := longest.clone()
mut res := []int{}
for e in shortest {
ix := index_of(longest2, e)
if ix >= 0 {
res << e
longest2 << longest2[ix+1..]
}
}
return res
}
fn common_n(ll [][]int) []int {
n := ll.len
if n == 0 {
return []int{}
}
if n == 1 {
return ll[0]
}
mut res := common2(ll[0], ll[1])
if n == 2 {
return res
}
for l in ll[2..] {
res = common2(res, l)
}
return res
}
fn main() {
lls := [
[[2, 5, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 9, 8, 4], [1, 3, 7, 6, 9]],
[[2, 2, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 2, 2, 4], [2, 3, 7, 6, 2]],
]
for ll in lls {
println("Intersection of $ll is:")
println(common_n(ll))
println('')
}
}</syntaxhighlight>
{{out}}
<pre>Intersection of [[2, 5, 1, 3, 8, 9, 4, 6] [3, 5, 6, 2, 9, 8, 4] [1, 3, 7, 6, 9]] is:
[3, 6, 9]
 
Intersection of [[2 2 1 3 8 9 4 6] [3 5 6 2 2 2 4] [2, 3, 7, 6, 2]] is:
[3, 6, 2, 2]</pre>
 
'''Alternative:'''
<syntaxhighlight lang="vlang">fn main()
{
lls := [
[[2, 5, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 9, 8, 4], [1, 3, 7, 6, 9]],
[[2, 2, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 2, 2, 4], [2, 3, 7, 6, 2]],
]
for ll in lls {
println("Intersection of $ll is:")
println(common_list_elements(ll))
println('')
}
 
}
 
fn common_list_elements(md_arr [][]int) []int {
mut counter := map[int]int{}
mut output := []int{}
 
for sd_arr in md_arr {
for value in sd_arr {
if counter[value] == counter[value] {counter[value] = counter[value] + 1} else { 1 } {
if counter[value] >= md_arr.len && output.any(it == value) == false {
output << value
}
}
}
}
return output
}</syntaxhighlight>
{{out}}
<pre>Intersection of [[2, 5, 1, 3, 8, 9, 4, 6] [3, 5, 6, 2, 9, 8, 4] [1, 3, 7, 6, 9]] is:
[3, 6, 9]
 
Intersection of [[2, 2, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 2, 2, 4], [2, 3, 7, 6, 2]] is:
[2, 3, 6]</pre>
 
=={{header|Wren}}==
{{libheader|Wren-seq}}
As we're dealing here with lists rather than sets, some guidance is needed on how to deal with duplicates in each list in the general case. A drastic solution would be to remove all duplicates from the result. Instead, the following matches duplicates - so if List A contains 2 'a's and List B contains 3 'a's, there would be 2 'a's in the result.
<langsyntaxhighlight ecmascriptlang="wren">import "./seq" for Lst
 
var common2 = Fn.new { |l1, l2|
Line 737 ⟶ 1,363:
System.print(commonN.call(ll))
System.print()
}</langsyntaxhighlight>
 
{{out}}
Line 746 ⟶ 1,372:
Intersection of [[2, 2, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 2, 2, 4], [2, 3, 7, 6, 2]] is:
[2, 3, 6, 2]
</pre>
<br>
Since the above was written, we can also now offer a library based solution.
<syntaxhighlight lang="wren">import "./seq" for Lst
 
var lls = [
[[2, 5, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 9, 8, 4], [1, 3, 7, 6, 9]],
[[2, 2, 1, 3, 8, 9, 4, 6], [3, 5, 6, 2, 2, 2, 4], [2, 3, 7, 6, 2]]
]
 
for (ll in lls) {
System.print(Lst.intersect(ll[0], Lst.intersect(ll[1], ll[2])))
}</syntaxhighlight>
 
{{out}}
<pre>
[3, 9, 6]
[2, 2, 3, 6]
</pre>
 
=={{header|XPL0}}==
A 32-bit integer is used to specify a set of values 0..31.
The [-1] terminator helps determine the number of lists.
<syntaxhighlight lang="xpl0">int IntSize, Nums, Sets, Ans, N, ListSize, Set, I;
[IntSize:= @Nums - @IntSize; \number of bytes in an integer
Nums:= [[2,5,1,3,8,9,4,6], [3,5,6,2,9,8,4], [1,3,7,6,9], [-1]];
Sets:= 0; \find the number of lists = number of Sets
while Nums(Sets, 0) > 0 do Sets:= Sets+1;
Ans:= -1;
for N:= 0 to Sets-1 do
[ListSize:= (Nums(N+1) - Nums(N)) / IntSize;
Set:= 0;
for I:= 0 to ListSize-1 do \Set = union (or) of list elements
Set:= Set or 1<<Nums(N, I);
Ans:= Ans & Set; \Answer is intersection (&) of Sets
];
I:= 0;
while Ans do \show common list elements
[if Ans & 1 then
[IntOut(0, I); ChOut(0, ^ )];
Ans:= Ans>>1;
I:= I+1;
];
]</syntaxhighlight>
 
{{out}}
<pre>
3 6 9
</pre>
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