先进先出页面置换算法（FIFO）代码与运行效果图

以下是使用Python实现FIFO页面置换算法的代码：

# FIFO page replacement algorithm

# Function to check if a page is present in memory
def search(memory, page):
    for i in range(len(memory)):
        if memory[i] == page:
            return True
    return False

# Function to replace page in memory
def replace(memory, page):
    memory.pop(0)
    memory.append(page)

# Function to simulate FIFO page replacement algorithm
def fifo(pages, frames):
    # Initialize memory and page fault counter
    memory = []
    page_faults = 0
    
    # Loop through each page in the sequence
    for page in pages:
        # If page is not in memory, replace a page
        if not search(memory, page):
            # If memory is not full, add page to memory
            if len(memory) < frames:
                memory.append(page)
            # If memory is full, replace the first page added
            else:
                replace(memory, page)
            # Increment page fault counter
            page_faults += 1
    
    # Return total number of page faults
    return page_faults

# Test the FIFO function
pages = [1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5]
frames = 3
page_faults = fifo(pages, frames)
print("Total page faults:", page_faults)

运行效果图如下：

Total page faults: 9

其中，`pages`表示页面访问序列，`frames`表示内存中页面帧数，`page_faults`表示页面错误次数。上面的代码打印出了内存帧数为3时，FIFO算法的总页面错误次数为9。