OS LRU PROGRAM

#include<stdio.h>

main()

{

int q[20],p[50],c=0,c1,d,f,i,j,k=0,n,r,t,b[20],c2[20];

printf("Enter no of pages:");

scanf("%d",&n);

printf("Enter the reference string:");

for(i=0;i<n;i++)

            scanf("%d",&p[i]);

printf("Enter no of frames:");

scanf("%d",&f);

q[k]=p[k];

printf("\n\t%d\n",q[k]);

c++;

k++;

for(i=1;i<n;i++)

            {

 c1=0;

  for(j=0;j<f;j++)

{

    if(p[i]!=q[j])

      c1++;

     }

      if(c1==f)

      {

     c++;

   if(k<f)

   {

   q[k]=p[i];

                                       

  k++;   

for(j=0;j<k;j++)

 printf("\t%d",q[j]);

                                                

printf("\n");

   }

  else

  {

  for(r=0;r<f;r++)

   {

 c2[r]=0

 for(j=i-1;j<n;j--)

  {                                                            if(q[r]!=p[j])

 c2[r]++;

    else

   break;

   }

    }

 for(r=0;r<f;r++)

  b[r]=c2[r];

    for(r=0;r<f;r++)

     {

     for(j=r;j<f;j++)

 {

  if(b[r]<b[j])

 {

                                                                        t=b[r];

                                                                        b[r]=b[j];

                                                                        b[j]=t;

   }

                                              

 }

                                 

  }

                                  

 for(r=0;r<f;r++)

                                   

 {

                                             

  if(c2[r]==b[0])

                                             

  q[r]=p[i];

                                             

  printf("\t%d",q[r]);

                                    

}

                                  

 printf("\n");

                      

 }

          

 }

}

printf("\nThe no of page faults is %d",c);

}