Question

Let`s suppose we have a simple (non-assoc) array with 100001 values and these values set in unsorted order like 45, 12, 32, 23. We know that in this array is 1 couple of numbers, how to find it optimally – not via 2 foreach loops and even not via 2 for loops with 100001/2 division?

Answer 1

Use array_count_values:

$result=array_count_values($arr);
$value=array_search(2, $result);

print $value;