①FIFO先进先出的页面淘汰算法 ②LRU最近最少使用页面淘汰算法 ③OPT最佳页面淘汰算法 ④LFU最不经常使用页面淘汰算法 ⑤NUR最近没有使用页面淘汰算法，各算法的伪代码

1. FIFO先进先出的页面淘汰算法

伪代码：

for each page in pages do
    if page not in page_table then
        if page_table is not full then
            add page to page_table
        else
            remove the oldest page from page_table
            add page to page_table
        end if
    end if
end for

2. LRU最近最少使用页面淘汰算法

伪代码：

for each page in pages do
    if page not in page_table then
        if page_table is not full then
            add page to page_table
        else
            find the least recently used page in page_table
            replace it with the current page
        end if
    else
        update the time stamp of the current page in page_table
    end if
end for

3. OPT最佳页面淘汰算法

伪代码：

for each page in pages do
    if page not in page_table then
        if page_table is not full then
            add page to page_table
        else
            find the page in page_table that will not be used for the longest time period in the future
            replace it with the current page
        end if
    end if
end for

4. LFU最不经常使用页面淘汰算法

伪代码：

for each page in pages do
    if page not in page_table then
        if page_table is not full then
            add page to page_table
        else
            find the page in page_table that has been accessed the least number of times
            replace it with the current page
        end if
    else
        increment the access count of the current page in page_table
    end if
end for

5. NUR最近没有使用页面淘汰算法

伪代码：

for each page in pages do
    if page not in page_table then
        if page_table is not full then
            add page to page_table
        else
            find the page in page_table that has the lowest NUR score (i.e., has not been referenced and has the lowest age)
            replace it with the current page
        end if
    else
        set the referenced bit of the current page in page_table to 1
    end if
    set the age bit of all pages in page_table to 0
end for