Question

How to find all common elements in given three sorted arrays with PHP

Answer 1

function PrintCommonElementsInThreeArrays($arr1, $arr2, $arr3) {
    $size1 = count($arr1);
    $size2 = count($arr2);
    $size3 = count($arr3);
        
    $i = 0;
    $j = 0;
    $k = 0;
        
    while ($i < $size1 && $j < $size2 && $k < $size3) {
        if ($arr1[$i] == $arr2[$j] && $arr3[$k] == $arr1[$i]) {
            echo $arr1[$i] . " ";
            $i++;
            $j++;
            $k++;
        }
        else if ($arr1[$i] < $arr2[$j]) {
            $i++;
        }
        else if ($arr2[$j] < $arr3[$k]) {
            $j++;
        }
        else {
            $k++;
        }
    }
}

$arr1 = array(2, 5, 6, 7, 9, 12, 20, 25, 30, 31);
        
$arr2 = array(4, 7, 10, 11, 20, 21, 30, 31, 37);
        
$arr3 = array(1, 2, 5, 7, 9, 18, 19, 20, 31, 32, 38, 39, 40, 50);
        
PrintCommonElementsInThreeArrays($arr1, $arr2, $arr3);




/*
run:

7 20 31 

*/

 

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