C-LOOK.cpp

#include<bits/stdc++.h>

int find(int d[],int n,int disk)
{
for(int i=0;i<n-1;i++)
  {
    if(d[i]>disk)
    {
      return i;
      break;
    }
  }
}

int main()
{
 int i,j,n;
 int disk;   //loc of head
 int temp,max;
 int dloc;   //loc of disk in array
 int no_t;

 printf("enter total number of tracks\n");
 scanf("%d",&no_t);

 printf("enter number of location\n");
 scanf("%d",&n);

 int d[n+1]; //disk queue

 printf("enter position of head\n");
 scanf("%d",&disk);

 printf("enter elements of disk queue\n");
 for(i=0;i<n;i++)
 {
 scanf("%d",&d[i]);
 }



 for(i=0;i<n-1;i++)    // sorting disk locations
 {
  for(j=i+1;j<n;j++)
  {
    if(d[i]>d[j])
    {
    temp=d[i];
    d[i]=d[j];
    d[j]=temp;
    }
  }
 }

 printf("elements after sorting\n");

 for(i=0;i<n;i++)
 {
 printf("%d ",d[i]);
 }

 int prev_head;
 printf("\nenter previous head position\n");
 scanf("%d",&prev_head);

 int c;
 int sum=0;

 if(prev_head>disk)
    c=1;
 else
    c=2;

//go towards left
 if(c==1)
 {
  int previous = find(d,n,disk);

   previous = previous-1;

   //printf("previous=%d\n",previous);

   sum+=abs(disk-d[previous]);

   //printf("sum=%d\n",sum);

   printf("%d->",disk);

   for(i=previous;i>=0;i--)
   {
    printf("%d ->",d[i]);
    if(i!=0)
    {
       int dr=abs(d[i]-d[i-1]);
       sum+=dr;
       //printf("sum=%d\n",sum);
    }
   }

   for(i=n-1;i>=previous+1;i--)
   {
       printf("%d ->",d[i]);

       if(i!=previous+1)
       {
        int dr=abs(d[i]-d[i-1]);
        sum+=dr;
   //     printf("sum=%d\n",sum);
       }
   }


   printf("\nmovement of total cylinders %d\n",sum);
 }

 //go towards right
else if(c==2)
{
  int previous = find(d,n,disk);

   printf("%d\n",previous);

   sum+=abs(d[previous]-disk);

   printf("%d->",disk);

   for(i=previous;i<n;i++)
   {
    printf("%d ->",d[i]);
    if(i!=n-1)
       sum+=abs(d[i+1]-d[i]);
   }

   for(i=0;i<=previous-1;i++)
   {
       printf("%d ->",d[i]);

       if(i!=previous-1)
        sum+=abs(d[i+1]-d[i]);
   }



   printf("\nmovement of total cylinders %d\n",sum);
}

return 0;
}