Question

I have a problem that I have been thinking about, but I can’t really figure out how to solve it. I am writing software for my local sports club, which has an international tourney coming up soon. I would like to have the administration as automised as possible. I have done a great deal already, but now I’m struggling to get one last thing done.

Say, you have an array with 4 teams, namely team A, B, C and D. What I would like to do, is to create a new array, with all possible games. That isn’t so hard to do, but the difficulty lies in the fact that I would like to have some sort of sorting capability in it. The way I have it now, the games are created like this:

['A - B', 'A - C', 'A - D', 'B - C' , ...]

What I would like to have is something like this:

['A - B', 'C - D', 'A - C', 'B - D', 'A - D', ...]

Does anyone know how I could achieve this? any help would be greatly appreciated.

Sidenote: A – B = B – A, We don’t need a two-way competition (but I can program this bit myself if necessary).

Answer 1

I have found the solution to my problem.
it is shown below 🙂

function sort_array($teams)
{
    $num_teams = count($teams);
    if(count($teams)%2 != 0)
    {
        $ghost = array();
        $ghost["name"] = "ghost";

        array_push($teams, $ghost);
        $num_teams++;
    }

    $games = array();
    for($i = 1; $i < $num_teams; $i++)
    {
        if($teams[$i]["name"] != "ghost")
                array_push($games, $teams[0]["name"] . " - " . $teams[$i]["name"]);

        for($k = 1; $k <= $num_teams; $k++)
        {
            $index_team_1 = ($i+$k < $num_teams) ? $i+$k : $i+$k-$num_teams;
            $index_team_2 = ($i-$k > 0) ? $i-$k : $i-$k+$num_teams-1;

            $temp_add = array();
            $temp_add["team_1"] = $teams[$index_team_1]["name"];
            $temp_add["team_2"] = $teams[$index_team_2]["name"];

            if($teams[$index_team_1]["name"] != "ghost" && 
                $teams[$index_team_2]["name"] != "ghost" &&
                $index_team_1 != 0 &&
                $index_team_2 != 0 &&
                $temp_add["team_1"] != $temp_add["team_2"] &&
                !in_array($temp_add["team_1"] . " - " . $temp_add["team_2"], $games) &&
                !in_array($temp_add["team_2"] . " - " . $temp_add["team_1"], $games))
                {
                    array_push($games, $temp_add["team_1"] . " - " . $temp_add["team_2"]);
                }
        }
    }

    return $games;
}