# 案例：开一家奶茶店

# 你是一家奶茶店老板，要制作三种饮品：

#

# 🍓 奶昔（N1）

#

# 🍫 巧克力奶茶（N2）

#

# 🍋 柠檬绿茶（N3）

#

# 每种饮品都需要不同的原材料，比如：

#

# R1：牛奶

#

# R2：糖

#

# R3：茶叶

#

# 你每天只进货固定量的原材料，比如：

#

# 牛奶：10升

#

# 糖：8公斤

#

# 茶叶：6包

import numpy as np, time

def solve_milk_tea_problem():

A = np.array([[2, 1, 0],

[1, 2, 1],

[0, 1, 2]])

b = np.array([10, 1, 2])

x = np.linalg.solve(A, b)

print(f"奶昔：{x[0]:.0f} 杯，巧克力奶茶：{x[1]:.0f} 杯，柠檬绿茶：{x[2]:.0f} 杯")

import pandas as pd

import matplotlib.pyplot as plt

def analyze_sales():

# Step 1: Create sales data

data = {

'Date': ['2025-10-01', '2025-10-02', '2025-10-03'],

'Milkshake': [20, 25, 22],

'ChocolateMilkTea': [15, 18, 20],

'LemonGreenTea': [10, 12, 15]

}

df = pd.DataFrame(data)

# Step 2: Convert date strings to datetime objects

df['Date'] = pd.to_datetime(df['Date'])

# Step 3: Calculate total daily sales

df['TotalSales'] = df[['Milkshake', 'ChocolateMilkTea', 'LemonGreenTea']].sum(axis=1)

# Step 4: Print summary

print("Daily Sales Summary:")

print(df)

# Step 5: Plot total sales trend

plt.figure(figsize=(8, 5))

plt.plot(df['Date'], df['TotalSales'], marker='o', label='Total Sales')

plt.title('Daily Total Sales Trend')

plt.xlabel('Date')

plt.ylabel('Cups Sold')

plt.grid(True)

plt.legend()

plt.tight_layout()

plt.show()

def range_test():

a = list(range(1000000))

b = np.array(a)

# list

start = time.time()

c = [x * 2 for x in a]

print("list time:", time.time() - start)

# numpy

start = time.time()

d = b * 2

print("numpy time:", time.time() - start)

# Run the main function

if __name__ == "__main__":

# analyze_sales()

# solve_milk_tea_problem()

# print(pd.__version__)

# print(np.__version__)

range_test()