One of the Rugby Coaches at my school have asked me to code a conditional rugby match draw for the upcoming games with the task laid out something like this: Given a list of teams from 1 - 12 split into 3 groups ([Group1 = 1, 2, 3, 4], [Group2 = 5, 6, 7, 8,], [Group3 = 9, 10, 11, 12]) generate and print an 11 round-robin matchup with the conditions that:
Teams in Group1 verses every other team in Group 1 twice (Eg. 1v2, 2v1, 1v3, 3v1, 1v4, 4v1, 1v5, 5v1.....)
This same rule applies to teams in Group3 as they verse other teams in Group3
I have attempted multiple times but inevitably become stuck, below are my 2 attempts:
Attempt 1:
import operator
import functools
import random
###First Generation (Flawed unclean round robin)
def fixtures(teams):
if len(teams) % 2:
teams.append('Day off') # if team number is odd - use 'day off' as fake team
rotation = list(teams) # copy the list
random.shuffle(rotation)
fixtures = []
for i in range(0, len(teams)-1):
fixtures.append(rotation)
rotation = [rotation[0]] + [rotation[-1]] + rotation[1:-1]
return fixtures
def main():
# demo code
teams = ["Team1","Team2","Team3","Team4","Team5","Team6","Team7","Team8","Team9","Team10","Team11","Team12"]
groupA = ["Team1","Team2","Team3","Team4"]
groupB = ["Team5","Team6","Team7","Team8"]
groupC = ["Team9","Team10","Team11","Team12"]
# for one match each - use this block only
matches = fixtures(teams)
print("flawed matches:")
RoundCounter = 0
homeTeams = []
awayTeams = []
for f in matches:
#print(f)
homeTeams = f[::2]
awayTeams = f[1::2]
print("Home Teams:{}".format(homeTeams))
print("Away Teams:{}".format(awayTeams))
HomeTeamGroupA = set(homeTeams).intersection(groupA)
HomeTeamGroupC = set(homeTeams).intersection(groupC)
AwayTeamGroupA = set(awayTeams).intersection(groupA)
AwayTeamGroupC = set(awayTeams).intersection(groupC)
VSCounter = 0
for p, o in zip(homeTeams, awayTeams):
if p in HomeTeamGroupA:
if o in AwayTeamGroupC:
AvsCPosition = awayTeams.index(o)
VSCounter += 1
RoundCleanUp(homeTeams, awayTeams, AvsCPosition, VSCounter) #if this is returned begin cleaning the round
else: print("GroupA is versing either Group B or GroupA") #if this is returned it is a team 1-4 but is vs either group b or group a
elif p in HomeTeamGroupC:
if o in AwayTeamGroupA:
AvsCPosition = awayTeams.index(o)
VSCounter += 1
RoundCleanUp(homeTeams, awayTeams, AvsCPosition, VSCounter) #if this is returned begin cleaning the round
else:
print("GroupC is versing either Group B or GroupC") #if this is returned it is a team 9-12 but is vs either group b or group c
else:
pass
def RoundCleanUp(HTeam, ATeam, AvsCPos, VSCounter):
##gets Value of List at position
HTeamVal = HTeam[AvsCPos]
ATeamVal = ATeam[AvsCPos]
main()
Attempt 2:
import operator
import functools
import random
def make_round(rotation, num_teams, fixtures):
for i in range(num_teams - 1):
rotation = list(range(1, num_teams + 1))
# clip to 0 .. num_teams - 2 # if i == 0, no rotation is needed (and using -0 as list index will cause problems)
i %= (num_teams - 1)
if i:
rotation = rotation[:1] + rotation[-i:] + rotation[1:-i]
half = num_teams // 2
fixtures.append(list(rotation[:half]))
fixtures.append(list(rotation[half:][::-1]))
return fixtures
def make_schedule(teams):
"""Produces RoundRobin"""
# number of teams must be even
TeamLength = len(teams)
if TeamLength % 2:
TeamLength += 1 # add a dummy team for padding
# build first round-robin
rotation = list(teams)
Fixture = []
schedule = make_round(rotation, TeamLength, Fixture)
return schedule
def homeAwayRotation(matches):
for homeTeams, awayTeams in zip(matches[0::2], matches[1::2]):
print("Home Rotation: {}".format(homeTeams))
print("Away Rotation: {}".format(awayTeams))
validation(homeTeams, awayTeams)
def validation(homeTeams, awayTeams):
groupA = [1, 2, 3, 4]
groupC = [9, 10, 11, 12]
for x, y in zip(homeTeams, awayTeams):
if x in groupA:
if y in groupC:
AvsCPosition = awayTeams.index(y)
cleanDirtyData(homeTeams, awayTeams, AvsCPosition)
else:
# if this is returned it is a team 1-4 but is vs either group b or group a
print("Group A vsing either itself or GroupB\n")
elif x in groupC:
if y in groupA:
AvsCPosition = awayTeams.index(y)
cleanDirtyData(homeTeams, awayTeams, AvsCPosition)
else:
# if this is returned it is a team 9-12 but is vs either group b or group c
print("Group C vsing either itself or GroupB\n")
else:
# if this is returned it is a team in group B
print("This is team B\n")
def cleanDirtyData(homeTeams, awayTeams, AvsCPosition):
HTeamVal = homeTeams[AvsCPosition]
ATeamVal = awayTeams[AvsCPosition]
Dirtlist = []
Dirtlist.append(HTeamVal)
Dirtlist.append(ATeamVal)
def main():
# demo code
teams = ["Team1", "Team2", "Team3", "Team4", "Team5", "Team6",
"Team7", "Team8", "Team9", "Team10", "Team11", "Team12"]
# for one match each - use this block only
matches = make_schedule(teams)
print("flawed matches:")
homeAwayRotation(matches)
main()
My expected results would be printing each round showing which team is versing which and each team having a history a bit like this:
a team in Group1 has a verse history of: (in any random order)
1v2, 2v1, 1v3, 3v1, 1v4, 4v1, 1v5, 1v6, 1v7, 1v8, bye
a team in Group2 has a verse history of: (in any random order)
5v1, 5v2, 5v3, 5v4, 5v6, 5v7, 5v8, 5v9 5v10, 5v11, 5v12
a team in Group3 has a verse history of: (in any random order)
9v10, 10v9, 9v11, 11v9, 9v12, 12v9, 9v5, 9v6, 9v7, 9v8, bye
Any pointers or improvements I could possibly do would be greatly appreciated as I have been stuck on the final hurdle for the last 2 weeks
If I have understood the problem correct, then all you need is some combining of teams with every member in different groups.
I put some code together that should solve your problem:
def vs(team, group):
matchups = map(lambda opponent: (team,opponent), group)
matchups = filter(lambda tup: tup[0] != tup[1], matchups)
return list(matchups)
def matches(teams):
group_size = len(teams) // 3
# Make the groups, basically just splitting the team list in three parts
groups = [teams[:group_size], teams[group_size:2*group_size], teams[2*group_size:]]
matchups = []
for index, team in enumerate(teams):
group_index = index // group_size
current_matchup = []
# Check if we're working with group 1 or 3
if group_index == 0 or group_index == 2:
# Flip the order of a tuple
def flip(x):
return (x[1], x[0])
own_group = vs(team, groups[group_index])
# Add matches against everyone in the group
current_matchup.extend(own_group)
# Add matches agains everyone in the group again, but now the current team is 'away'
current_matchup.extend(list(map(flip, own_group)))
# Add matches against everyone in group 2
current_matchup.extend(vs(team, groups[1]))
# Lastly, add the bye
current_matchup.append((team, "bye"))
else:
# Just all matches against all other teams, once.
current_matchup.extend(vs(team, teams))
matchups.append(current_matchup)
return matchups
# This can be anything. Numbers, 'Team 1' or even 'The wondrous flying squirrels of death'
teams = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]
# Make matches
matchups = matches(teams)
# Just pretty print
for i in range(len(matchups)):
matches = '\n\t'.join(map(lambda m: f'{str(m[0]).rjust(10)} vs {str(m[1]).ljust(10)}', matchups[i]))
print(f"Team '{teams[i]}' matches:\n\t{matches}")