Disk scheduling

[aruljothi]

#include<stdio.h>
#include<conio.h>
#include<math.h>
#include<graphics.h>

main()
{
   int gd=DETECT,gm,x,y,a1,x1,y1,a,b;
   int req[30],head,i,k,move,n,ch,t1,t2,max,min,g[30],c,h;
   initgraph(&gd,&gm,"z:\tcpp\bgi");
   /*int req[30],head,i,k,move,n,ch,t1,t2,max,min,g[30],c,h;*/
   clearviewport();
   printf("(1) LOOK   (2) CLOOK   (3) FCFS   (0) EXIT
Enter your choice:
");
   scanf("%d",&ch);

   while(ch)
   {
      printf("Enter the current head position: ");
      scanf("%d",&head); h=head;
      printf("Enter the number of requests: ");
      scanf("%d",&n); k=0; move=0;
      printf("Total number of cylinders: 200.
");
      printf("Enter the requests (1 to 200):
");
req:
      for(i=0;i<n;i++)
      {
         scanf("%d",&req);
         if(req>200||req<1)
         { printf("Enter requests only between 1-200."); goto req; }
      }

      switch(ch)
      {
      case 1:
      outtextxy(270,10,"SEEK PATTERN FOR LOOK");
      max=req[0]; min=req[0]; t2=1; c=0;
      for(i=1;i<n;i++)
      {
         max=max>req?max:req;
         min=min<req?min:req;
      }
      if(max<=head) t2=0;
      while(k<n)
      {
         t1=0;
         for(i=0;i<n;i++)
         {
            if(t2)
            {
               if(req&&req>=head)
               {
                  if(req<req[t1]) t1=i;
                  if(req==max)
                  { t2=0; g[c]=1; c++; }
               }
            }

            else
            {
               if(req&&req<=head)
               {
                  if(req>req[t1]) t1=i;
                  if(req==min)
                  { t2=1; g[c]=200; c++; }
               }
            }
         }/*for*/
         printf("%d ",req[t1]);
         g[c]=req[t1]; c++;
         move+=abs(head-req[t1]);
         req[t1]=0; k++;
         head=req[t1];
         if(head==max) t2=0;
      }/*while*/
      break;

      case 2:
      outtextxy(270,10,"SEEK PATTERN FOR CLOOK");
      max=req[0]; min=req[0]; t2=1; c=0;
      for(i=1;i<n;i++)
      {
         max=max>req?max:req;
         min=min<req?min:req;
      }
      while(k<n)
      {
         t1=0;
         if(!t2) head=min;
         for(i=0;i<n;i++)
         {
            if(req&&req>=head)
            {
               if(req<req[t1]) t1=i;
               else if(req==max)
               { head=1; g[c]=1; c++; }
            }
         }/*for*/
         printf("%d ",req[t1]);
         move+=abs(head-req[t1]);
         head=req[t1];
         g[c]=req[t1]; c++;
         req[t1]=0; k++;
         if(head==max) t2=0;
      }/*while*/
      break;

      case 3:
      outtextxy(270,10,"SEEK PATTERN FOR FCFS");
      for(i=0,c=0;i<n;i++,c++)
      {
         printf("%d ",req);
         move+=abs(head-req);
         head=req;
         g[c]=req;
      }
      break;
      }/*switch*/
      printf("Order of servicing:
");
      printf("%d: ",h);
      for(i=0;i<n;i++)
         printf("%d ",g);
      printf("
Total Head Movements: %d
",move);
      x=getmaxx();
      y=getmaxy();
      rectangle(0,20,x-5,y-5);

      a1=(x-30)/10;

      b=110; a=h+(3*a1); y1=125;
      fillellipse(a,b,2,2);


      for(i=0;i<n;i++)
      {
      int x1=g+(3*a1);
      fillellipse(x1,y1,2,2);
      line(a,b,x1,y1);
      a=x1; b=y1;
      y1+=15;
      }

      getch();
      clrscr(); clearviewport();
      printf("
(1) LOOK   (2) CLOOK   (3) FCFS   (0) EXIT
Enter your choice:
");
      scanf("%d",&ch);
   }/*while*/
getch();
}/*main*/