某产品的价格是800元/件，但若购买量大可给予一定的折扣：够100(含100，下同)件时打9折，够200件打85折，够300件打82折，够500件打8折，请用嵌套的if-else语句编程求解应收款。 不允许使用并列（平等）的if，即：所有的if必须都嵌套

要编写一个满足条件的嵌套if-else语句来计算购买特定数量商品后的应收款，可以按照以下步骤进行：

# 定义商品价格和折扣率
price_per_item = 800
discount_rates = {
    100: 0.9,
    200: 0.85,
    300: 0.82,
    500: 0.8
}

def calculate_total_amount(quantity):
    if quantity >= 500:
        discount_rate = discount_rates[500]
    elif quantity >= 300:
        discount_rate = discount_rates[300]
    elif quantity >= 200:
        discount_rate = discount_rates[200]
    elif quantity >= 100:
        discount_rate = discount_rates[100]
    else:
        # 如果购买数量小于100件，则按原价计算，无折扣
        discount_rate = 1

    total = quantity * price_per_item * discount_rate
    return total

# 示例：计算购买400件商品的总金额
quantity_to_buy = 400
total_amount = calculate_total_amount(quantity_to_buy)
print(f"购买 {quantity_to_buy} 件商品的应收款为：{total_amount}元")

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