I have an array in the following format:
array(
0 => array(1, 5),
1 => array(4, 8),
2 => array(19, 24),
3 => array(6, 9),
4 => array(11, 17),
);
Where each item is a X-to-Y range. What I would like to merge the overlapping ranges in the array, to get something more like this:
array(
0 => array(1, 9), // 1-5, 4-8 and 6-9 are overlapping, so they are merged
1 => array(11, 17),
2 => array(19, 24),
);
What would be the best way to accomplish this?
Untested, but the idea here is to sort the data first by the first element, then merge subsequent elements with the previous one as long as possible.
usort($data, function($a, $b)
{
return $a[0] - $b[0];
});
$n = 0; $len = count($data);
for ($i = 1; $i < $len; ++$i)
{
if ($data[$i][0] > $data[$n][1] + 1)
$n = $i;
else
{
if ($data[$n][1] < $data[$i][1])
$data[$n][1] = $data[$i][1];
unset($data[$i]);
}
}
$data = array_values($data);
[1,2],[3,4] to be one single range of [1,4]. In that case, it would read if (3 > 2 + 1) then start a new range. With floating point numbers, it's not really useful. The +1, can be dropped or set to a very small delta (+.00001), depending on what you consider small enough to be the same number.
strtotime() everywhere except second if() block (obviously!) and add 60 (i.e 60 sec) instead of 1 in first if() block).. would love to see(as update) if there is a better approach for merging datetime ranges (not desperate enough to post a new question though).$input = array( 0 => array(1, 5),
1 => array(4, 8),
2 => array(19, 24),
3 => array(6, 9),
4 => array(11, 17),
);
$tmpArray = array();
foreach($input as $rangeSet) {
$tmpArray = array_unique(array_merge($tmpArray,range($rangeSet[0],$rangeSet[1])));
}
sort($tmpArray);
$oldElement = array_shift($tmpArray);
$newArray = array(array($oldElement));
$ni = 0;
foreach($tmpArray as $newElement) {
if ($newElement > $oldElement+1) {
$newArray[$ni++][] = $oldElement;
$newArray[$ni][] = $newElement;
}
$oldElement = $newElement;
}
$newArray[$ni++][] = $oldElement;
var_dump($newArray);
Alright, drafted this up, so it may have quirks. Tested it with the data seen below and seemed to work just fine. May not be the best way to do it, but it is one way and it does work. Questions let me know.
function combineRange($array) {
if (is_array($array)) {
// Sort the array for numerical order
sort($array);
// Set Defaults
$prev = array();
$prev_key = null;
foreach ($array as $key => $item) {
// First time around setup default data
if (empty($prev)) {
$prev = $item;
$prev_key = $key;
continue;
}
if ($item[0] >= $prev[0] && $item[0] <= $prev[1]) {
// Incase the last number was less than do not update
if ($array[$prev_key][1] < $item[1])
$array[$prev_key][1] = $item[1];
unset($array[$key]);
}else {
$prev_key = $key;
}
$prev = $item;
}
}
return $array;
}
$array = array(
5 => array(13, 16),
0 => array(1, 5),
1 => array(4, 8),
2 => array(19, 24),
3 => array(6, 9),
4 => array(11, 17),
6 => array(21, 30),
);
var_dump(combineRange($array));
Outputs:
array(3) {
[0]=>
array(2) {
[0]=>
int(1)
[1]=>
int(9)
}
[3]=>
array(2) {
[0]=>
int(11)
[1]=>
int(17)
}
[5]=>
array(2) {
[0]=>
int(19)
[1]=>
int(30)
}
}
Hope it works for ya!
EDIT
I see I was beaten out by an hour =\ Oh well! I am still posting as it is a different method, granted I would probably choose konforce's method instead.
