Python: Calculate the maximum profit from selling and buying values of stock

Last update on May 24 2025 10:49:03 (UTC/GMT +8 hours)

Max Profit from Stocks

Write a Python program to calculate the maximum profit from selling and buying values of stock. An array of numbers represent the stock prices in chronological order.
For example, given [8, 10, 7, 5, 7, 15], the function will return 10, since the buying value of the stock is 5 dollars and sell value is 15 dollars.

Sample Solution:

Python Code:

# Define a function to calculate the maximum profit from buying and selling stocks
def buy_and_sell(stock_price):
    # Initialize variables to store the maximum profit and current maximum value
    max_profit_val, current_max_val = 0, 0
    
    # Iterate through the reversed stock prices
    for price in reversed(stock_price):
        # Update the current maximum value with the maximum of the current value and the previous maximum
        current_max_val = max(current_max_val, price)
        
        # Calculate the potential profit by subtracting the current price from the current maximum value
        potential_profit = current_max_val - price
        
        # Update the maximum profit with the maximum of the potential profit and the previous maximum profit
        max_profit_val = max(potential_profit, max_profit_val)

    # Return the maximum profit
    return max_profit_val

# Test the function with different stock price lists and print the results
print(buy_and_sell([8, 10, 7, 5, 7, 15]))  # Maximum Profit: 10
print(buy_and_sell([1, 2, 8, 1]))           # Maximum Profit: 7
print(buy_and_sell([]))                      # Maximum Profit: 0

Sample Output:

10
7
0

Explanation:

Here is a breakdown of the above Python code:

• The function "buy_and_sell()" calculates the maximum profit from buying and selling stocks.
• It iterates through the reversed 'stock_price' list, starting from the end.
• For each price, it updates the 'current_max_val' with the maximum of the current value and the previous maximum.
• It calculates the potential profit by subtracting the current price from the 'current_max_val'.
• It updates the 'max_profit_val' with the maximum of the potential profit and the previous maximum profit.
• The function returns the final maximum profit value.
• Test the function with different stock price lists and print the results.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Python program to calculate the maximum profit from stock prices with a single buy and sell transaction.
• Write a Python program to determine the best days to buy and sell stock to achieve the maximum profit using a one-pass algorithm.
• Write a Python program to compute the optimal profit by tracking the minimum price and calculating potential gains at each step.
• Write a Python program to find the maximum profit from a series of stock prices by iterating through the price list only once.

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Python Code Editor:

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