Write a C++ program to implement LRU algorithm.

C++Program to implement LRU algorithm

//  main.cpp

//  quicksort

//

#include<iostream>

#define max 100

class lrupagereplacement

{

   

   private:

   

    int frame[10], count[10], cstr[max];

   

    int tot,nof,fault;

   

   public:

   

 lrupagereplacement (){fault=0;}

   

    void getdata();

   

    void push();

   

    void dis();

   

};

void lrupagereplacement::getdata()

{

   

    int pno,i=0;

   

   

    std::cout<<"\n Enter No. of Page Frames:";

   

    std::cin>>nof;

   

    std::cout<<"\n Enter the Context String:(Press -1 to end)\n";

   

    do

       

    {

       

        std::cin>>pno;

       

        cstr[i++]=pno;

       

    }while(pno!=-1);

   

    tot=i-1;

   

}

void lrupagereplacement::push()

{

   

    int x,i,flag=0,nc=0,maximum,maxpos=-1,mark=0;

   

    for(i=0;i<nof;i++)

       

    {

       

        frame[i]=-1;

       

        count[i]=mark--;

       

    }

   

    for(i=0;i<tot;i++)

       

    {

       

        flag=0;

       

        x=cstr[i];

       

        nc++;

       

        for(int j=0; j<nof; j++)

           

        {

           

            for(int k=0; k<nof;k++)

               

                count[k]++;

           

            if(frame[j]==x)

               

            {

               

                flag=1;

               

                count[j]=1;

               

                break;

               

            }

           

        }

       

        if(flag==0)

           

        {

           

            maximum = 0;

           

            for(int k=0;k<nof;k++)

               

            {

               

                if(count[k]>maximum && nc>nof)

                   

                {

                   

                    maximum=count[k];

                   

                    maxpos = k;

                   

                }

                

            }

           

            if(nc>nof)

               

            {

               

                frame[maxpos]=x;

               

                count[maxpos]=1;

               

            }

           

            else

               

                frame[nc-1]=x;

           

            fault++;

           

            std::cout<<"\nThe Page Fault No:"<<fault;

           

            dis();

           

        }

       

    }

   

    std::cout<<"\nTotal Page Faults :"<<fault;

   

}

void lrupagereplacement::dis()

{

   

    int i=0;

   

    std::cout<<"\n-\n";

   

    while(i<nof)

       

    {

       

        std::cout<<"|   "<<frame[i]<<"   ";

       

        i++;

       

    }

   

    std::cout<<"|";

}

int main()

{

   

 lrupagereplacement lru;

   

 lrupagereplacement.getdata();

   

 lrupagereplacement.push();

   

 return 0;

}

SAMPLE OUTPUT

Enter No. of Page Frames:4

Enter the Context String:(Press -1 to end)

1 2 3 4 2 5 9 -1

The Page Fault No1

-

|   1   |   -1   |   -1   |   -1   |

The Page Fault No2

-

|   1   |   2   |   -1   |   -1   |

The Page Fault No3

-

|   1   |   2   |   3   |   -1   |

The Page Fault No4

-

|   1   |   2   |   3   |   4   |

The Page Fault No5

-

|   5   |   2   |   3   |   4   |

The Page Fault No6

-

|   5   |   2   |   9   |   4   |

Total Page Faults :6Program ended with exit code: 0