过滤数组的键？ php扑克

Now I know the basic logic behind finding a straight, and I assume that would include a pseudo of

   function is_straight(array $cards) {
        sort($cards);

        if(($cards[4] - $cards[0]) == 5) {
                            //Code to make sure the cards in between are increment
            //is straight.
        }
   }

would theoretically work for a 5 card check.

But how would one go for eliminating cards from the array of 7 cards to find a straight?

Would I have to individually check all 5 hand combinations within the 7 cards array?

so eliminate two cards from the $cards array and check that combination for a straight?

So I'm a little stuck on the logical side of this, rather than the code side.

In pseudo code

#filter doubles
cards = array_unique(cards)
sort(cards)

foreach cards as key, value:    

    if not key_exists(cards, key+4):
        return false

    if cards[key+4] == value + 4:
        return true

longer potentially more explicit version

#filter doubles
cards = array_unique(cards)
sort(cards)

straight_counter = 1

foreach cards as key, value:    

    if not key_exists(cards, key+1):
        return false

    # is the following card an increment to the current one
    if cards[key+1] == value + 1:
        straight_counter++
    else:
        straight_counter = 1            

    if straight_counter == 5:
        return true

Assuming that $cards is an array containing cards values from 1 to 13, I think you need to evaluate with a difference of 4, not 5 :

5 - 1 = 4
6 - 2 = 4
7 - 3 = 4
etc.

You also need to add a specific logic for 10, J, Q, K, A

But for your specific question, what about :

function is_straight(array $cards) {
    sort($cards);

    if((($cards[4] - $cards[0]) == 4) || 
       (($cards[5] - $cards[1]) == 4) || 
       (($cards[6] - $cards[2]) == 4)) {
                        //Code to make sure the cards in between are increment
        //is straight.
    }
}

    function is_straight(array $array) {
        $alpha = array_keys(array_count_values($array));

        sort($alpha);

        if (count($alpha) > 4) {
            if (($alpha[4] - $alpha[0]) == 4) {
                $result = $alpha[4];
                return $result;
            }
            if (count($alpha) > 5) {
                if (($alpha[5] - $alpha[1]) == 4) {
                    $result = $alpha[5];
                    return $result;
                }
            }
            if (count($alpha) > 6) {
                if (($alpha[6] - $alpha[2]) == 4) {
                    $result = $alpha[6];
                    return $result;
                }
            }
        }
    }