PHP递归统计优化技巧

$categories = [
    [
        'id' => 1,
        'name' => '家电',
        'product_count' => 2,
        'children' => [
            [
                'id' => 2,
                'name' => '电视',
                'product_count' => 5,
                'children' => []
            ],
            [
                'id' => 3,
                'name' => '冰箱',
                'product_count' => 3,
                'children' => [
                    ['id' => 4, 'name' => '迷你冰箱', 'product_count' => 1, 'children' => []]
                ]
            ]
        ]
    ]
];

function countProducts($category) {
    $total = $category['product_count'];
    foreach ($category['children'] as $child) {
        $total += countProducts($child);
    }
    return $total;
}
// 调用
echo countProducts($categories[0]); // 输出: 11

function countProductsIterative($root) {
    $total = 0;
    $stack = [$root];

    while (!empty($stack)) {
        $node = array_pop($stack);
        $total += $node['product_count'];
        foreach ($node['children'] as $child) {
            $stack[] = $child;
        }
    }

    return $total;
}