Question

Need this in C++. Thanks.

OBJECTIVE

The purpose of this programming project is to explore page replacement algorithms. This can be achieved by implementing the LRU and Optimal algorithms as described in our textbook and discussed in class.

This project is worth 100 points.

PROJECT SPECIFICATIONS

Review the LRU and Optimal algorithms discussed in class and Chapter 9 from the book. Your program must be named "paging" and will read a list of page numbers from a file. The name of the file will be passed to your program as a command line argument. The example input file contains three lists of page numbers:

2, 6, 9, 2, 4, 2, 1, 7, 3, 0, 5, 2, 1, 2, 9, 5, 7, 3, 8, 5

0, 6, 3, 0, 2, 6, 3, 5, 2, 4, 1, 3, 0, 6, 1, 4, 2, 3, 5, 7

                        3, 1, 4, 2, 5, 4, 1, 3, 5, 2, 0, 1, 1, 0, 2, 3, 4, 5, 0, 1

Your program will output the page number in each frame for each page fault with the given frames by following in a standardized format.

1. Echo the list of page numbers.
2. Echo the algorithm used (LRU or Optimal).
3. Echo the total given frames.
4. For each page fault, output the page number in each frame
5. Output the total number of page faults.

Here is how the program should be run (3 is the number of frames).

% paging input.txt LRU 3

Input page numbers: 2,6,9,2,4,2,1,7,3,0,5,2,1,2,9,5,7,3,8,5

Page replace algorithm: LRU

Given frame number: 3

Processing page 2, page fault 1: 2, -1, -1

Processing page 6, page fault 2: 2, 6, -1

Processing page 9, page fault 3: 2, 6, 9

Processing page 2, no page fault

                 .

                 .

                 .

Total page faults is: 17                

Sample input is provided however you should test your program with different list of page numbers. Output may be different if you use stack.

Answer 1

#include<iostream>
#include<bits/stdc++.h>
#include <fstream>
using namespace std;

bool search(int key, vector<int>& vec)
{
    for (int i = 0; i < vec.size(); i++)
        if (vec[i] == key)
            return true;
    return false;
}

int predict(int pages[], vector<int>& vec, int n, int index)
{
    int result = -1, farthest = index;
    for (int i = 0; i < vec.size(); i++) {
        int j;
        for (j = index; j < n; j++) {
            if (vec[i] == pages[j]) {
                if (j > farthest) {
                    farthest = j;
                    result = i;
                }
                break;
            }
        }

        if (j == n)
            return i;
    }
    return (result == -1) ? 0 : result;
}

int optimalPage(int pages[], int n, int capacity)
{
       cout<<"Given frame number: "<<capacity<<endl;
    vector<int> vec;
       vector<int>::iterator it;
       int page_faults=0;
    for (int i = 0; i < n; i++)
       {
               cout<<"Processing page "<<pages[i]<<",";
        if (search(pages[i], vec)) {
                       cout<<"no page fault: "<<endl;
            continue;
        }
        if (vec.size() < capacity)
        {
                   vec.push_back(pages[i]);
                   page_faults++;
                   cout<<"page fault "<<page_faults<<": ";
               }
        else
               {
            int j = predict(pages, vec, n, i + 1);
            vec[j] = pages[i];
                       page_faults++;
                       cout<<"page fault "<<page_faults<<": ";
        }
        for(int j=0; j<capacity; j++)
           {
               cout<<vec[j]<<", ";
           }
           cout<<endl;
    }
       return page_faults;

}

int modstack(int pages[], int n, int capacity)
{
   cout<<"Given frame number: "<<capacity<<endl;
   vector<int> vec;
   vector<int>::iterator it;
   int page_faults=0;
   for(int i=0;i<n;i++)
   {
       cout<<"Processing page "<<pages[i]<<",";
       if(vec.capacity()<capacity)
       {
           if(find(vec.begin(),vec.end(),pages[i])==vec.end())
           {
               vec.insert(vec.begin(),pages[i]);
               page_faults++;
               cout<<"page fault "<<page_faults<<": ";
           }
           else
           {
               vec.erase(find(vec.begin(),vec.end(),pages[i]));
               vec.insert(vec.begin(),pages[i]);
               cout<<"no page fault: "<<endl;
        continue;
           }
       }
       else
       {
           if(find(vec.begin(),vec.end(),pages[i])==vec.end())
           {
               vec.pop_back();
               vec.insert(vec.begin(),pages[i]);
               page_faults++;
               cout<<"page fault "<<page_faults<<": ";
           }
           else
           {
               vec.erase(find(vec.begin(),vec.end(),pages[i]));
               vec.insert(vec.begin(),pages[i]);
               cout<<"no page fault: "<<endl;
        continue;
           }
       }
       for(it=vec.begin();it!=vec.end();++it)
       {
           cout<<*it<<",";
       }
       cout<<endl;
   }
   return page_faults;
}

void getArray(string str)
{
    int l = str.length();
    int arr[l];
    for(int i=0;i<l;i++) arr[i]=0;
    int j = 0, i;
    l=0;
    for (i = 0; str[i] != '\0'; i++)
       {
           if (str[i] == ',') continue;
      else if (str[i] == ' ') continue;
      else {arr[l] = arr[l] * 10 + (str[i] - 48); l++;}
    }
       int capacity, n, page_faults,page_faults1;
       cout<<"Page replace algorithm: LRU"<<endl;
       capacity = 3;
       page_faults = modstack(arr,l,capacity);
       cout<<"Total page faults is:"<<page_faults<<endl;
    cout<<"\n\n";
       cout<<"Page replace algorithm: Optimal"<<endl;
       capacity = 3;
       page_faults1 = optimalPage(arr,l,capacity);
       cout<<"Total page faults is:"<<page_faults1<<"\n"<<endl;
}

int main()
{
   string pages[3],line;
int count=0;
   ifstream inFile ("paging.txt");
   if (inFile.is_open())
   {
       while (! inFile.eof() )
       {
           getline (inFile,line);

           if(count<3)
      {
        cout<<"Input page numbers: "<<line<<endl;
        getArray(line);
        count++;
      }
       }
       inFile.close();
   }

   else
   {
           cout << "Unable to open file";
           exit(1);
   }
}