Program in C to show LRU page replacement algorithm

#include<stdio.h>

#include<conio.h>

int i,j,nof,nor,flag=0,ref[50],frm[50],pf=0,victim=-1;

int recent[10],lrucal[50],count=0;

int lruvictim();

void main()

{

  clrscr();

  printf("\n\t\t\t LRU PAGE REPLACEMENT ALGORITHM");

  printf("\n Enter no.of Frames....");

  scanf("%d",&nof);

  printf(" Enter no.of reference string..");

  scanf("%d",&nor);

  printf("\n Enter reference string..");

  for(i=0;i<nor;i++)

  scanf("%d",&ref[i]);

  printf("\n\n\t\t LRU PAGE REPLACEMENT ALGORITHM ");

  printf("\n\t The given reference string:");

  printf("\n………………………………..");

  for(i=0;i<nor;i++)

  printf("%4d",ref[i]);

  for(i=1;i<=nof;i++)

  {

    frm[i]=-1;

    lrucal[i]=0;

  }

  for(i=0;i<10;i++)

   recent[i]=0;

   printf("\n");

   for(i=0;i<nor;i++)

   {

     flag=0;

     printf("\n\t Reference NO %d->\t",ref[i]);

     for(j=0;j<nof;j++)

     {

      

        if(frm[j]==ref[i])

       {

             flag=1;

             break;

       }

     }

     if(flag==0)

     {

       count++;

       if(count<=nof)

       victim++;

       else

       victim=lruvictim();

       pf++;

       frm[victim]=ref[i];

       for(j=0;j<nof;j++)

       printf("%4d",frm[j]);

     }

     recent[ref[i]]=i;

   }

   printf("\n\n\t No.of page faults...%d",pf);

   getch();

}

int lruvictim()

{

  int i,j,temp1,temp2;

  for(i=0;i<nof;i++)

  {

    temp1=frm[i];

    lrucal[i]=recent[temp1];

  }

  temp2=lrucal[0];

  for(j=1;j<nof;j++)

  {

    if(temp2>lrucal[j])

    temp2=lrucal[j];

  }

  for(i=0;i<nof;i++)

  if(ref[temp2]==frm[i])

  return i;

  return 0;

}

OUTPUT

Program in C to show first ii firt out page replacement algorithm

#include<stdio.h>

#include<conio.h>

int i,j,nof,nor,flag=0,ref[50],frm[50],pf=0,victim=-1;

void main()

{           

 clrscr();

 printf("\n \t\t\t FIFI PAGE REPLACEMENT ALGORITHM");

 printf("\n Enter no.of frames....");

 scanf("%d",&nof);

 printf("Enter number of reference string..\n");

 scanf("%d",&nor);

 printf("\n Enter the reference string..");

 for(i=0;i<nor;i++)

 scanf("%d",&ref[i]);

 printf("\nThe given reference string:");

 for(i=0;i<nor;i++)

 printf("%4d",ref[i]);

 for(i=1;i<=nof;i++)

 frm[i]=-1;

 printf("\n");

 for(i=0;i<nor;i++)

 {

   flag=0;

   printf("\n\t Reference np%d->\t",ref[i]);

   for(j=0;j<nof;j++)

   {

     if(frm[j]==ref[i])

     {

       flag=1;

       break;

     }}

      if(flag==0)

   {

     pf++;

     victim++;

     victim=victim%nof;

     frm[victim]=ref[i];

     for(j=0;j<nof;j++)

     printf("%4d",frm[j]);

   }

 }

 printf("\n\n\t\t No.of pages faults...%d",pf);

 getch();

}

OUTPUT

Program in C to show multiprogramming fixed task

#include<stdio.h>

#include<conio.h>

main()

{

            int ms,i,ps[20],n,size,p[20],s,intr=0;

            clrscr();

            printf("Enter size of memory:");

            scanf("%d",&ms);

            printf("Enter memory for OS:");

            scanf("%d",&s);

            ms-=s;

            printf("Enter no.of partitions to be divided:");

            scanf("%d",&n);

            size=ms/n;

            for(i=0;i<n;i++)

            {

                        printf("Enter process and process size");

                        scanf("%d%d",&p[i],&ps[i]);

                        if(ps[i]<=size)

                        {

                                    intr=intr+size-ps[i];

                                    printf("process%d is allocated\n",p[i]);

                        }

                        else

                                    printf("process%d is blocked",p[i]);

            }

            printf("total fragmentation is %d",intr);

            getch();

}

OUTPUT

Program in C to show multiprogramming variable task

#include<stdio.h>

#include<conio.h>

main()

{             

            int i,m,n,tot,s[20];

            clrscr();

            printf("Enter total memory size:");

            scanf("%d",&tot);

            printf("Enter no. of pages:");

            scanf("%d",&n);

            printf("Enter memory for OS:");

            scanf("%d",&m);

            for(i=0;i<n;i++)

            {

                        printf("Enter size of page%d:",i+1);

                        scanf("%d",&s[i]);

            }

            tot=tot-m;

            for(i=0;i<n;i++)

            {

                        if(tot>=s[i])

                        {

                                    printf("Allocate page %d\n",i+1);

                                    tot=tot-s[i];

                        }

                        else

                                    printf("process p%d is blocked\n",i+1);

            }

            printf("External Fragmentation is=%d",tot);

            getch();

}

Output

Program in C to show linked file allocation

#include<stdio.h>

#include<conio.h>

struct file

{

 char fname[10];

 int start,size,block[10];

}f[10];

main()

{

 int i,j,n;

 clrscr();

 printf("Enter no. of files:");

 scanf("%d",&n);

 for(i=0;i<n;i++)

 {

 printf("Enter file name:");

 scanf("%s",&f[i].fname);

 printf("Enter starting block:");

 scanf("%d",&f[i].start);

 f[i].block[0]=f[i].start;

 printf("Enter no.of blocks:");

 scanf("%d",&f[i].size);

 printf("Enter block numbers:");

 for(j=1;j<=f[i].size;j++)

 {

          scanf("%d",&f[i].block[j]);

 }

 }

 printf("File\tstart\tsize\tblock\n");

 for(i=0;i<n;i++)

 {

          printf("%s\t%d\t%d\t",f[i].fname,f[i].start,f[i].size);

          for(j=1;j<=f[i].size-1;j++)

                   printf("%d--->",f[i].block[j]);

          printf("%d",f[i].block[j]);

          printf("\n");

 }

 getch();

}

Output