Find Intersection Algorithm Using PHP

Joy Joel
2 min readSep 20, 2022

Have the function FindIntersection(strArr) read the array of strings stored in strArr which will contain 2 elements: the first element will represent a list of comma-separated numbers sorted in ascending order, the second element will represent a second list of comma-separated numbers (also sorted). Your goal is to return a comma-separated string containing the numbers that occur in elements of strArr in sorted order. If there is no intersection, return the string false.

<?phpfunction FindIntersection($strArr) {  $array1 = explode(", ", $strArr[0]);  $array2 = explode(", ", $strArr[1]);  $intersect = [];    foreach ($array1 as $data) {

if (in_array($data, $array2)) {
$intersect[] = $data;
}
} return (empty($intersect)) ? "false" : implode(",", $intersect); return $strArr;}// echo the function call hereecho FindIntersection();?>output logs will look like this:1,4,13

The explode function is used to “Split a string into pieces of elements to form an array”, in simple term, it breaks a string into an array.

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Joy Joel

Abba’s Daughter| DevOps Engineer|Technical Writer