Disk Scheduling Algorithm (Complete)

#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[i]);
if(req[i]>200||req[i]<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[i]?max:req[i];
min=min<req[i]?min:req[i];
}
if(max<=head) t2=0;
while(k<n)
{
t1=0;
for(i=0;i<n;i++)
{
if(t2)
{
if(req[i]&&req[i]>=head)
{
if(req[i]<req[t1]) t1=i;
if(req[i]==max)
{ t2=0; g[c]=1; c++; }
}
}

else
{
if(req[i]&&req[i]<=head)
{
if(req[i]>req[t1]) t1=i;
if(req[i]==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[i]?max:req[i];
min=min<req[i]?min:req[i];
}
while(k<n)
{
t1=0;
if(!t2) head=min;
for(i=0;i<n;i++)
{
if(req[i]&&req[i]>=head)
{
if(req[i]<req[t1]) t1=i;
else if(req[i]==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[i]);
move+=abs(head-req[i]);
head=req[i];
g[c]=req[i];
}
break;
}/*switch*/
printf("Order of servicing:
");
printf("%d: ",h);
for(i=0;i<n;i++)
printf("%d ",g[i]);
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[i]+(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*/