检测重叠时期的PHP

时间:2016-06-13 11:10:15

标签: php period

你可以帮我解决重叠时期吗?我有阵列

["1-9","11-15","14-20","8-11"]

数组中的每个元素的周期。最小 - 1个周期,最多 - 阵列中的10个周期。我需要检测它们是否重叠。

我从另一个问题中找到了这个案例

image

2 个答案:

答案 0 :(得分:0)

这是一个简单的片段,其检查方式基于比较第一个范围的最高端到第二个范围的最低端(如果我们只考虑范围有效)。首先,分拣范围起着重要作用:

$ranges = ["1-9","11-15","14-20","8-11"];
$results = [];
sort($ranges, SORT_NUMERIC);
foreach ($ranges as $first) {
    $firstNums = explode("-", $first);
    foreach ($ranges as $second) {
        if ($first == $second) continue;
        $secondNums = explode("-", $second);
        if ($firstNums[1] >= $secondNums[0] && $first != end($ranges)) {
            $results[$first] = $second;
        }
    }
}
print_r($results);

结果(包含两个重叠的日期):

Array
(
    [1-9] => 8-11
    [8-11] => 11-15
    [11-15] => 14-20
)

答案 1 :(得分:0)

这应该涵盖所有情况:

<?php

public function findOverlappingPeriods(array $periods): array
{
    $overlappingItems = [];

    foreach ($periods as $keyA => $periodA) {
        foreach ($periods as $keyB => $periodB) {
            if ($keyA === $keyB) {
                continue;
            }

            if ($periodB['start'] > $periodA['start'] && $periodB['start'] < $periodA['end']) {
                $overlappingItems[] = $keyA;
                $overlappingItems[] = $keyB;
            }
        }
    }

    return $overlappingItems;
}