Round-robin tournament schedule: Difference between revisions

From Rosetta Code
Content added Content deleted
(Added XPL0 example.)
(Added Wren)
Line 96: Line 96:
1 3 4 5 6 7
1 3 4 5 6 7
2 12 11 10 9 8
2 12 11 10 9 8
</pre>

=={{header|Wren}}==
{{libheader|Wren-fmt}}
<lang ecmascript>import "./fmt" for Fmt

var rotateRight = Fn.new { |lst|
var last = lst[-1]
for (i in lst.count-1..1) lst[i] = lst[i-1]
lst[0] = last
}

var rotateLeft = Fn.new { |lst|
var first = lst[0]
for (i in 1...lst.count) lst[i-1] = lst[i]
lst[-1] = first
}

var roundRobin = Fn.new { |n|
var lst1 = (2..n).toList
var lst2 = (n..2).toList
var rounds = n - 1
if (n % 2 == 1) {
lst1 = lst1 + [0]
lst2 = [0] + lst2 // 0 denotes a bye
rounds = n
}
var n2 = rounds / 2
for (round in 1..rounds) {
Fmt.write("Round $2d", round)
var lst3 = [1] + lst1
for (i in 0...n2) Fmt.write(" ($2d vs $-2d)", lst3[i], lst2[i])
System.print()
rotateRight.call(lst1)
rotateLeft.call(lst2)
}
}

System.print("Round robin for 12 players:\n")
roundRobin.call(12)
System.print("\n\nRound robin for 5 players (0 denotes a bye) :\n")
roundRobin.call(5)</lang>

{{out}}
<pre>
Round robin for 12 players:

Round 1 ( 1 vs 12) ( 2 vs 11) ( 3 vs 10) ( 4 vs 9 ) ( 5 vs 8 ) ( 6 vs 7 )
Round 2 ( 1 vs 11) (12 vs 10) ( 2 vs 9 ) ( 3 vs 8 ) ( 4 vs 7 ) ( 5 vs 6 )
Round 3 ( 1 vs 10) (11 vs 9 ) (12 vs 8 ) ( 2 vs 7 ) ( 3 vs 6 ) ( 4 vs 5 )
Round 4 ( 1 vs 9 ) (10 vs 8 ) (11 vs 7 ) (12 vs 6 ) ( 2 vs 5 ) ( 3 vs 4 )
Round 5 ( 1 vs 8 ) ( 9 vs 7 ) (10 vs 6 ) (11 vs 5 ) (12 vs 4 ) ( 2 vs 3 )
Round 6 ( 1 vs 7 ) ( 8 vs 6 ) ( 9 vs 5 ) (10 vs 4 ) (11 vs 3 ) (12 vs 2 )
Round 7 ( 1 vs 6 ) ( 7 vs 5 ) ( 8 vs 4 ) ( 9 vs 3 ) (10 vs 2 ) (11 vs 12)
Round 8 ( 1 vs 5 ) ( 6 vs 4 ) ( 7 vs 3 ) ( 8 vs 2 ) ( 9 vs 12) (10 vs 11)
Round 9 ( 1 vs 4 ) ( 5 vs 3 ) ( 6 vs 2 ) ( 7 vs 12) ( 8 vs 11) ( 9 vs 10)
Round 10 ( 1 vs 3 ) ( 4 vs 2 ) ( 5 vs 12) ( 6 vs 11) ( 7 vs 10) ( 8 vs 9 )
Round 11 ( 1 vs 2 ) ( 3 vs 12) ( 4 vs 11) ( 5 vs 10) ( 6 vs 9 ) ( 7 vs 8 )


Round robin for 5 players (0 denotes a bye) :

Round 1 ( 1 vs 0 ) ( 2 vs 5 ) ( 3 vs 4 )
Round 2 ( 1 vs 5 ) ( 0 vs 4 ) ( 2 vs 3 )
Round 3 ( 1 vs 4 ) ( 5 vs 3 ) ( 0 vs 2 )
Round 4 ( 1 vs 3 ) ( 4 vs 2 ) ( 5 vs 0 )
Round 5 ( 1 vs 2 ) ( 3 vs 0 ) ( 4 vs 5 )
</pre>
</pre>


Revision as of 20:41, 14 November 2021

Round-robin tournament schedule is a draft programming task. It is not yet considered ready to be promoted as a complete task, for reasons that should be found in its talk page.

A round-robin tournament is also known as an all-play-all-tournament; each participant plays every other participant once.

For N participants the number of rounds is N-1 if N is an even number. When there are an odd number of participants then each round one contestor has no opponent (AKA as a "bye"). The number of rounds is N in that case.

Task

Write a program that prints out a tournament schedule for 12 participants (represented by numbers 1 to 12).

See also


Raku

<lang perl6>my @players = 1..12; my $half = +@players div 2; my $round = 0;

loop { 

   printf "Round %2d: %s\n", ++$round, "{ zip( @players[^$half], @players[$half..*].reverse ).map: { sprintf "(%2d vs %-2d)", |$_ } }";
   @players[1..*].=rotate(-1);
   last if [<] @players;

}</lang>

Output:
Round  1: ( 1 vs 12) ( 2 vs 11) ( 3 vs 10) ( 4 vs 9 ) ( 5 vs 8 ) ( 6 vs 7 )
Round  2: ( 1 vs 11) (12 vs 10) ( 2 vs 9 ) ( 3 vs 8 ) ( 4 vs 7 ) ( 5 vs 6 )
Round  3: ( 1 vs 10) (11 vs 9 ) (12 vs 8 ) ( 2 vs 7 ) ( 3 vs 6 ) ( 4 vs 5 )
Round  4: ( 1 vs 9 ) (10 vs 8 ) (11 vs 7 ) (12 vs 6 ) ( 2 vs 5 ) ( 3 vs 4 )
Round  5: ( 1 vs 8 ) ( 9 vs 7 ) (10 vs 6 ) (11 vs 5 ) (12 vs 4 ) ( 2 vs 3 )
Round  6: ( 1 vs 7 ) ( 8 vs 6 ) ( 9 vs 5 ) (10 vs 4 ) (11 vs 3 ) (12 vs 2 )
Round  7: ( 1 vs 6 ) ( 7 vs 5 ) ( 8 vs 4 ) ( 9 vs 3 ) (10 vs 2 ) (11 vs 12)
Round  8: ( 1 vs 5 ) ( 6 vs 4 ) ( 7 vs 3 ) ( 8 vs 2 ) ( 9 vs 12) (10 vs 11)
Round  9: ( 1 vs 4 ) ( 5 vs 3 ) ( 6 vs 2 ) ( 7 vs 12) ( 8 vs 11) ( 9 vs 10)
Round 10: ( 1 vs 3 ) ( 4 vs 2 ) ( 5 vs 12) ( 6 vs 11) ( 7 vs 10) ( 8 vs 9 )
Round 11: ( 1 vs 2 ) ( 3 vs 12) ( 4 vs 11) ( 5 vs 10) ( 6 vs 9 ) ( 7 vs 8 )

Ruby

<lang ruby>def round_robin( n ) 

 rotating_players = (2..n).map(&:to_s) #player 1 to be added later
 rotating_players << "bye" if n.odd? 
 Array.new(rotating_players.size) do |r|
   all = ["1"] + rotating_players.rotate(-r)
   [all[0, all.size/2], all[all.size/2..].reverse]
 end

end

round_robin(12).each.with_index(1) do |round, i| 

 puts "Round #{i}"
 round.each do |players|
   puts players.map{|player| player.ljust(4)}.join
 end
 puts

end </lang>

Output:
Round 1
1   2   3   4   5   6   
12  11  10  9   8   7   

Round 2
1   12  2   3   4   5   
11  10  9   8   7   6   

Round 3
1   11  12  2   3   4   
10  9   8   7   6   5   

Round 4
1   10  11  12  2   3   
9   8   7   6   5   4   

Round 5
1   9   10  11  12  2   
8   7   6   5   4   3   

Round 6
1   8   9   10  11  12  
7   6   5   4   3   2   

Round 7
1   7   8   9   10  11  
6   5   4   3   2   12  

Round 8
1   6   7   8   9   10  
5   4   3   2   12  11  

Round 9
1   5   6   7   8   9   
4   3   2   12  11  10  

Round 10
1   4   5   6   7   8   
3   2   12  11  10  9   

Round 11
1   3   4   5   6   7   
2   12  11  10  9   8

Wren

Library: Wren-fmt

<lang ecmascript>import "./fmt" for Fmt

var rotateRight = Fn.new { |lst| 

   var last = lst[-1]
   for (i in lst.count-1..1) lst[i] = lst[i-1]
   lst[0] = last

}

var rotateLeft = Fn.new { |lst| 

   var first = lst[0]
   for (i in 1...lst.count) lst[i-1] = lst[i]
   lst[-1] = first

}

var roundRobin = Fn.new { |n| 

   var lst1 = (2..n).toList
   var lst2 = (n..2).toList
   var rounds = n - 1
   if (n % 2 == 1) {
       lst1 = lst1 + [0]
       lst2 = [0] + lst2 // 0 denotes a bye
       rounds = n
   }
   var n2 = rounds / 2
   for (round in 1..rounds) {
       Fmt.write("Round $2d", round)
       var lst3 = [1] + lst1
       for (i in 0...n2) Fmt.write(" ($2d vs $-2d)", lst3[i], lst2[i])
       System.print()
       rotateRight.call(lst1)
       rotateLeft.call(lst2)
   }

}

System.print("Round robin for 12 players:\n") roundRobin.call(12) System.print("\n\nRound robin for 5 players (0 denotes a bye) :\n") roundRobin.call(5)</lang>

Output:
Round robin for 12 players:

Round  1 ( 1 vs 12) ( 2 vs 11) ( 3 vs 10) ( 4 vs 9 ) ( 5 vs 8 ) ( 6 vs 7 )
Round  2 ( 1 vs 11) (12 vs 10) ( 2 vs 9 ) ( 3 vs 8 ) ( 4 vs 7 ) ( 5 vs 6 )
Round  3 ( 1 vs 10) (11 vs 9 ) (12 vs 8 ) ( 2 vs 7 ) ( 3 vs 6 ) ( 4 vs 5 )
Round  4 ( 1 vs 9 ) (10 vs 8 ) (11 vs 7 ) (12 vs 6 ) ( 2 vs 5 ) ( 3 vs 4 )
Round  5 ( 1 vs 8 ) ( 9 vs 7 ) (10 vs 6 ) (11 vs 5 ) (12 vs 4 ) ( 2 vs 3 )
Round  6 ( 1 vs 7 ) ( 8 vs 6 ) ( 9 vs 5 ) (10 vs 4 ) (11 vs 3 ) (12 vs 2 )
Round  7 ( 1 vs 6 ) ( 7 vs 5 ) ( 8 vs 4 ) ( 9 vs 3 ) (10 vs 2 ) (11 vs 12)
Round  8 ( 1 vs 5 ) ( 6 vs 4 ) ( 7 vs 3 ) ( 8 vs 2 ) ( 9 vs 12) (10 vs 11)
Round  9 ( 1 vs 4 ) ( 5 vs 3 ) ( 6 vs 2 ) ( 7 vs 12) ( 8 vs 11) ( 9 vs 10)
Round 10 ( 1 vs 3 ) ( 4 vs 2 ) ( 5 vs 12) ( 6 vs 11) ( 7 vs 10) ( 8 vs 9 )
Round 11 ( 1 vs 2 ) ( 3 vs 12) ( 4 vs 11) ( 5 vs 10) ( 6 vs 9 ) ( 7 vs 8 )


Round robin for 5 players (0 denotes a bye) :

Round  1 ( 1 vs 0 ) ( 2 vs 5 ) ( 3 vs 4 )
Round  2 ( 1 vs 5 ) ( 0 vs 4 ) ( 2 vs 3 )
Round  3 ( 1 vs 4 ) ( 5 vs 3 ) ( 0 vs 2 )
Round  4 ( 1 vs 3 ) ( 4 vs 2 ) ( 5 vs 0 )
Round  5 ( 1 vs 2 ) ( 3 vs 0 ) ( 4 vs 5 )

XPL0

<lang XPL0>def N = 12; \number of players (must be even) int I, Player(N+1), Round, Temp; [for I:= 1 to N do Player(I):= I; for Round:= 1 to N-1 do 

   [IntOut(0, Round);  ChOut(0, ^:);
   for I:= 1 to N/2 do
       [ChOut(0, 9\tab\);  IntOut(0, Player(I))];
   CrLf(0);
   for I:= N downto N/2+1 do
       [ChOut(0, 9\tab\);  IntOut(0, Player(I))];
   CrLf(0);  CrLf(0);
   Temp:= Player(N);   \rotate
   for I:= N-1 downto 2 do
       Player(I+1):= Player(I);
   Player(2):= Temp;
   ];

]</lang>

Output:
1:      1       2       3       4       5       6
        12      11      10      9       8       7

2:      1       12      2       3       4       5
        11      10      9       8       7       6

3:      1       11      12      2       3       4
        10      9       8       7       6       5

4:      1       10      11      12      2       3
        9       8       7       6       5       4

5:      1       9       10      11      12      2
        8       7       6       5       4       3

6:      1       8       9       10      11      12
        7       6       5       4       3       2

7:      1       7       8       9       10      11
        6       5       4       3       2       12

8:      1       6       7       8       9       10
        5       4       3       2       12      11

9:      1       5       6       7       8       9
        4       3       2       12      11      10

10:     1       4       5       6       7       8
        3       2       12      11      10      9

11:     1       3       4       5       6       7
        2       12      11      10      9       8
Retrieved from "https://rosettacode.org/wiki/Round-robin_tournament_schedule?oldid=317450"