#include <iostream>#include <vector>#include <algorithm>using namespace std;vector<int> LRU(vector<int> pages, int memory_size) { vector<int> memory; vector<int> ps; for (int i = 0; i < pages.size(); i++) { int page = pages[i]; auto it = find(memory.begin(), memory.end(), page); if (it != memory.end()) { // 如果页面已经在内存中，则将其移动到队列尾部 memory.erase(it); } else { // 如果内存已满，则移除队列头部的页面 if (memory.size() == memory_size) { int remove_page = ps.front(); ps.erase(ps.begin()); auto it = find(memory.begin(), memory.end(), remove_page); memory.erase(it); } } // 将新页面加入到队列尾部 memory.push_back(page); ps.push_back(page); } return ps;}int main() { vector<int> pages = {1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5}; int memory_size = 3; vector<int> ps = LRU(pages, memory_size); for (auto p : ps) { cout << p << " "; } return 0;}不显示页面

这段代码是 C++ 的代码，需要在编译器中运行才能看到结果。如果您在命令行中使用 g++ 编译器，可以使用以下命令编译代码：

g++ -o lru lru.cpp

然后使用以下命令运行代码：

./lru

这样就可以在命令行中看到程序输出的结果了。如果您在其他集成开发环境（IDE）中编写代码，可以使用 IDE 提供的运行和调试工具来查看代码的输出。

相关问题

Write the code about Program for Least Recently used Algorithm in C++.Requirements are as follows:1、 Create a page access sequence (page number range 0-18) using a random function. The sequence length is 54 and assume that the number of main memory frames allocated to the thread is 6, that is, M = 6. 2、 Implement the LRU algorithm for page replacement on the above access sequence. 3、 Output the page replacement sequence and the page fault rate.

Sure, here's the code:

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    const int N = 54; // length of page access sequence
    const int M = 6; // number of main memory frames
    const int P = 19; // page number range (0-18)

    // generate page access sequence randomly
    vector<int> page_seq;
    for (int i = 0; i < N; ++i) {
        page_seq.push_back(rand() % P);
    }

    // LRU algorithm
    vector<int> frames(M, -1); // initialize all frames to -1 (empty)
    vector<int> page_fault_seq; // record page faults
    int page_faults = 0;
    for (int i = 0; i < N; ++i) {
        int page = page_seq[i];
        auto it = find(frames.begin(), frames.end(), page); // check if page is already in memory
        if (it == frames.end()) { // page fault
            ++page_faults;
            if (frames[0] == -1) { // there is an empty frame
                frames[0] = page;
            } else { // no empty frame, need to evict the least recently used page
                int lru_page = frames.back(); // the last page in the frames is the LRU page
                frames.pop_back();
                frames.insert(frames.begin(), page); // insert the new page at the front
                page_fault_seq.push_back(lru_page);
            }
        } else { // page hit
            frames.erase(it);
            frames.insert(frames.begin(), page); // move the page to the front
        }
    }

    // output results
    cout << "Page replacement sequence: ";
    for (auto p : page_fault_seq) {
        cout << p << " ";
    }
    cout << endl;
    cout << "Page fault rate: " << static_cast<double>(page_faults) / N << endl;

    return 0;
}

Explanation:

- We first generate a page access sequence of length 54 using a random function. We assume that the page number range is 0-18.
- We then implement the LRU algorithm for page replacement on the above access sequence. We use a vector `frames` to represent the main memory frames, and initialize all frames to -1 (empty). We also use a vector `page_fault_seq` to record the page replacement sequence (i.e., the pages that are evicted from memory due to page faults).
- For each page in the access sequence, we check if it is already in memory. If it is, we move it to the front of `frames` (since it is the most recently used page). If it is not, we check if there is an empty frame. If there is, we simply put the page in that frame. If there is not, we evict the least recently used page (which is the last page in `frames`), and put the new page in the front of `frames`. We also record the evicted page in `page_fault_seq`.
- After processing the entire access sequence, we output the page replacement sequence and the page fault rate.

Note that the page fault rate may vary each time you run the program due to the randomness of the page access sequence.

windowsc++设计LRU页面置换算法的函数，以便演示LRU算法的页面置换过程(提示：LRU算法需频繁调整移动页号队列ps中元素的位置)。

以下是一个简单的实现LRU页面置换算法的函数：

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

vector<int> LRU(vector<int> pages, int memory_size) {
    vector<int> memory;
    vector<int> ps;

    for (int i = 0; i < pages.size(); i++) {
        int page = pages[i];
        auto it = find(memory.begin(), memory.end(), page);

        if (it != memory.end()) {
            // 如果页面已经在内存中，则将其移动到队列尾部
            memory.erase(it);
        } else {
            // 如果内存已满，则移除队列头部的页面
            if (memory.size() == memory_size) {
                int remove_page = ps.front();
                ps.erase(ps.begin());
                auto it = find(memory.begin(), memory.end(), remove_page);
                memory.erase(it);
            }
        }

        // 将新页面加入到队列尾部
        memory.push_back(page);
        ps.push_back(page);
    }

    return ps;
}

int main() {
    vector<int> pages = {1, 2, 3, 4, 1, 2, 5, 1, 2, 3, 4, 5};
    int memory_size = 3;
    vector<int> ps = LRU(pages, memory_size);

    for (auto p : ps) {
        cout << p << " ";
    }

    return 0;
}

在这个实现中，我们使用了两个队列：一个用于存储当前内存中的页面，另一个用于存储当前的页面顺序。每当一个新页面访问时，我们首先检查它是否已经在内存中。如果是，我们只需要将其移动到队列尾部。否则，我们需要将其加入到内存中，可能需要移除队列头部的页面。在每个步骤中，我们都将当前页面加入到队列尾部。最后，我们返回页面顺序队列，以便演示LRU算法的页面置换过程。