算法-零钱兑换

<?php
function getNeedConisNum(array $conis, $amount)
{
    if (empty($conis) || empty($amount)) {
        return -1;
    }
    rsort($conis);
    $find = $conis;
    $finish = [];
    while (!empty($find)) {
        if (empty($find)) {
            break;
        }
        $res = array_shift($find);
        if (!is_array($res)) {
            $res = array($res);
        }
        if (array_sum($res) == $amount) {
            $finish[] = count($res);
        }

        if (array_sum($res) > $amount) {
            continue;
        } else {
            foreach ($conis as $newConi) {
                $res[] = $newConi;
                $find[] = $res;
            }
        }
    }
    if (empty($finish)) {
        return -1;
    }
    return min($finish);
}

$conis = [1, 2, 5];
$amount = 11;
echo getNeedConisNum($conis, $amount);
echo "\n";
$conis = [2];
$amount = 3;
echo getNeedConisNum($conis, $amount);

结果

3
-1