PHP generate football schedule - php

Question

I have 38 days and 20 clubs (EPL).
How can I generate not repeated matches for this clubs in this days (schedule)?
For example:
Day 1:
club1 - club2
club3 - club4
...
club19 - club 20
Day 2:
club1 - club3
club2 - club4
...
club20 - club18
Each club plays with other two games (home and away). Respectively do not play with himself.
My thinks:
$clubs1 = array();
$clubs2 = array();
$days = range(1, 38);
$calendar = array();
$pars = array();
$rows = Yii::app()->db->createCommand()
->select('id')
->from('clubs')
->queryAll();
foreach ($rows as $item) {
$clubs1[] = $item['id'];
$clubs2[] = $item['id'];
}
shuffle($clubs1);
shuffle($clubs2);
$total = (count($clubs1) * 2) - 2;
for ($j = 1; $j <= $total; $j ++) {
$day = $days[$j];
for ($i = 0; $i < count($clubs1); $i++) {
WHAT I SHOULD DO IN THIS BODY?
}
}

Answer 1

You need only one clubs array
1) remove $clubs2
2) rename $clubs1 to $clubs
3) remove whole for structure
//for testing: $clubs=array(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20);
$countofteams=count($clubs);
$c=1;
for($j=0;$j<2;$j++) //home/away
for($i=1;$i<$countofteams;$i++){ //move teams
echo '----DAY '.$c++.'----<br>';
for($a=0;$a<$countofteams;$a++) //all teams are playing
echo 'Match '.$clubs[$a].' vs '.$clubs[($a+$i)%$countofteams].'<br>';
}

Answer 2

$team = array();
$pars = array();
$rows = Yii::app()->db->createCommand()
->select('id')
->from('clubs')
->queryAll();
foreach ($rows as $k => $item) {
$team[$k+1] = $item['id'];
}
$all_team = count($team);
$k = $all_team/2;
$days = range(7, 100, 2); // first halh of season
$days2 = range(55, 100, 2); // second half
// 1 tour
for ($i=1; $i <= $k; $i++) {
$pars[] = $days[0].'|'.$team[$i].'|'.$team[($all_team-$i+1)];
$pars[] = $days2[0].'|'.$team[($all_team-$i+1)].'|'.$team[$i];
}
// Next tours
for($i=2; $i<$all_team; $i++)
{
$team2 = $team[2];
for($y=2;$y<$all_team;$y++)
{
$team[$y] = $team[$y+1];
}
$team[$all_team] = $team2;
for($j=1;$j<=$k;$j++)
{
$pars[] = $days[$i - 1].'|'.$team[$j].'|'.$team[($all_team-$j+1)];
$pars[] = $days2[$i - 1].'|'.$team[($all_team-$j+1)].'|'.$team[$j];
}
}

Answer 3

Here's my solution, replace the $clubs array with your result set of club IDs from database. The only slight inaccuracy with real-world EPL is that the second half of the season will mirror the first half exactly.
See if this adaption of http://board.phpbuilder.com/showthread.php?10300945-Round-Robin-Generator is any better :) - just for first half of the season.
$clubs = array(
'che', 'swa', 'ast', 'manc', 'liv', 'tot', 'ars', 'sot', 'hul', 'stok', 'wham', 'qpr', 'sun', 'mutd', 'lei', 'new', 'eve', 'wba', 'cry', 'bur',
);
shuffle($clubs);
$num_players = count($clubs) - 1;
// Set the return value
$ret = '';
// Generate the pairings for each round.
for ($round = 0; $round < $num_players; $round++) {
$ret .= '<h3>' . ($round + 1) . '</h3>';
$players_done = array();
// Pair each player except the last.
for ($player = 1; $player < $num_players; $player++) {
if (!in_array($player, $players_done)) {
// Select opponent.
$opponent = $round - $player;
$opponent += ($opponent < 0) ? $num_players : 1;
$playerName = $clubs[$player];
$opponentName = $clubs[$opponent];
// Ensure opponent is not the current player.
if ($opponent != $player) {
// Choose colours.
if (($player + $opponent) % 2 == 0 xor $player < $opponent) {
// Player plays white.
$ret .= "$playerName - $opponentName $br";
} else {
// Player plays black.
$ret .= "$opponentName - $playerName $br";
}
// This pair of players are done for this round.
$players_done[] = $player;
$players_done[] = $opponent;
}
}
}
// Pair the last player.
if ($round % 2 == 0) {
$playerName = $clubs[$num_players];
$opponent = ($round + $num_players) / 2;
$opponentName = $clubs[$opponent];
// Last player plays white.
$ret .= "$playerName - $opponentName $br";
} else {
$opponent = ($round + 1) / 2;
// Last player plays black.
$ret .= "$opponentName - $playerName $br";
}
}
echo $ret;