I am trying to calculate the winning order of golfers when they are tied in a competition.
The rules are to use a "countback". i.e., if scores are tied after 9 holes, the best placed of the ties is the best score from the last 8 holes. then 7 holes, etc.
The best I can come up with is 2 arrays.
- An array with all the players who tied in a given round. ($ties)
- One which has the full score data in (referencing the database playerid) for all 9 holes. ($tie_perhole)
I loop through array 1, pulling data from array 2 and using the following formula to create a temporary array with the highest score:
$max = array_keys($array,max($array));
If $max only has 1 item, this player is the highest scorer. the loop through the first array is "by reference", so on the next iteration of the loop, his playerid is now longer in the array, thus ignored. this continues until there is only 1 playerid left in the first array.
However, it only works if a single player wins in each iteration. The scenario that doesn't work is if a sub-set of players tie on any iterations / countbacks.
I think my problem is the current structure I have will need the original $ties array to become split, and then to continue to iterate through the split arrays in the same way...
As an example...
The $ties array is as follows:
Array
(
[18] => Array
(
[0] => 77
[1] => 79
[2] => 76
[3] => 78
)
)
The $tie_perhole (score data) array is as follows:
Array
(
[18] => Array
(
[77] => Array
(
[9] => 18
[8] => 16
[7] => 14
[6] => 12
[5] => 10
[4] => 8
[3] => 6
[2] => 4
[1] => 2
)
[79] => Array
(
[9] => 18
[8] => 17
[7] => 15
[6] => 14
[5] => 11
[4] => 9
[3] => 7
[2] => 5
[1] => 3
)
[76] => Array
(
[9] => 18
[8] => 16
[7] => 14
[6] => 12
[5] => 10
[4] => 8
[3] => 6
[2] => 4
[1] => 2
)
[78] => Array
(
[9] => 18
[8] => 17
[7] => 15
[6] => 13
[5] => 11
[4] => 9
[3] => 7
[2] => 5
[1] => 3
)
)
)
So in this competition, player's 78 and 79 score highest on the 8th hole countback (17pts), so 1st and 2nd should be between them. Player 79 should then be 1st on the 6th hole countback (14pts, compared to 13pts). The same should occur for 3rd and 4th place with the 2 remaining other players.
There are other scenarios that can occur here, in that within a competition, there will likely be many groups of players (of different amounts) on different tied points through the leaderboard.
Also note, there will be some players on the leaderboard who are NOT tied and stay in their current outright position.
The basics of the working code I have is:
foreach ($ties as $comparekey => &$compareval) {
$tie_loop = 0;
for ($m = 9; $m >= 1; $m--) {
$compare = array();
foreach ($compareval as $tie) {
$compare[$tie] = $tie_perhole[$comparekey][$tie][$m];
}
$row = array_keys($compare,max($compare));
if (count($row) == 1) {
$indexties = array_search($row[0], $ties[$comparekey]);
unset($ties[$comparekey][$indexties]);
// Now update this "winners" finishing position in a sorted array
// This is a multidimensional array too, with custom function...
$indexresults = searchForId($row[0], $comp_results_arr);
$comp_results_arr[$indexresults][position] = $tie_loop;
$tie_loop++;
}
// I think I need conditions here to filter if a subset of players tie
// Other than count($row) == 1
// And possibly splitting out into multiple $ties arrays for each thread...
if (empty($ties[$comparekey])) {
break;
}
}
}
usort($comp_results_arr, 'compare_posn_asc');
foreach($comp_results_arr as $row) {
//echo an HTML table...
}
Thanks in advance for any helpful insights, tips, thoughts, etc...
