Add a discount on selected categories provided they are the second item in the cart

I am in the product cards to offer presales from specific categories with a discount.I found here such a code but it works even if there are only goods from these categories in the cart.

Is it possible to add a condition so that it works only when the cart already has at least 1 product not from the selected categories?

Example:
I added a category: Chairs, if the user goes to it and buys goods only from this category, the discount will not be applied, if he goes to any other category, for example, Tables, add the product Table to the cart and then when adding goods from the desired category Chairs, the discount will be applied. We want to give a discount, but only as an additional product.

/**
 * Добавление скидок на товар в корзине
 * @param WC_Cart $cart
 */
add_action( 'woocommerce_cart_calculate_fees', 'x_products_discount' );
function x_products_discount( $cart ) {
    // Settings below
    $categorise_ids = array(1795,1732,1725); // <== Your defined product Ids
    $percentage  = 10; // <== discount in percentage (10% here)

    $found_ids   = array();
    
    // Loop through cart items
    foreach (WC()->cart->get_cart() as $cart_item ) {
        // Loop through defined product Ids
        foreach( $product_ids as $product_id ) {
            if( in_array( $product_id, array( $cart_item['product_id'], $cart_item['variation_id'] ) ) ) {
                $found_ids[$product_id] = $product_id;
                break;
            }
        }
    }
    
    // Discount part
    if( count( $found_ids ) === count( $product_ids ) ) {
        $cart->add_fee( ( 'Скидка', 'woocommerce' ), -( $cart->subtotal * $percentage / 100 ) );
    }
}

Tried this code, it works, but we need it not to work if the cart only has the categories in the code

There are some mistakes in your code, try instead the following revisited code:

/**
 * Adding discounts to cart items
 * @param WC_Cart $cart
 */
function products_category_based_discount( $cart ) {
    // Settings below
    $categories_ids = array(1795,1732,1725); // <== Your defined product category Ids
    $percentage  = 10; // <== discount in percentage (10% here)
    $found_category = $found_other = false;
    
    // Loop through cart items
    foreach ( $cart->get_cart() as $item ) {
        if( has_term( $categories_ids, 'product_cat', $item['product_id'] ) ) {
            $found_category = true;
        } else {
            $found_other = true;
        }
    }
    
    // Discount part
    if( $found_category && $found_other ) {
        $cart->add_fee( __( 'Discount', 'woocommerce' ), -( $cart->subtotal * $percentage / 100 ) );
    }
}

add_action( 'woocommerce_cart_calculate_fees', 'products_category_based_discount' );

It should work.