C语言的磁盘调度算法

#include
#include
#include
#define null 0
#define len sizeof(struct cidaohao)

struct cidaohao
{
struct cidaohao *pre;
int num;
struct cidaohao *next;
};

FCFS(array)
int array[50];
{int i,j,sum=0;
printf("\nFCFS : ");
for(i=1;array[i]!=-1;i++)
{
printf(" %d ",array[i]);
}
i=0;
for(i=0,j=1;array[j]!=-1;i++,j++)
{
if(array[i]>array[j]) sum+=(array[i]-array[j]);
else sum+=(array[j]-array[i]);
}
return(sum);
}

SSTF(head,now)
struct cidaohao *head;
int now;
{struct cidaohao *p,*lp,*rp;
int sum=0,front,behind;
p=head;
printf("\nSSTF :");
while(p->num!=now) p=p->next;/* */
lp=p->pre;
rp=p->next;
do
{
if(p->next!=null&&p->pre!=null)
{ front=p->num-lp->num;
behind=rp->num-p->num;
if(front>=behind)
{
sum+=behind;
p=rp;
printf(" %d ",p->num);
rp=p->next;
}
else
{
sum+=front;
p=lp;
printf(" %d ",p->num);
lp=p->pre;
}
}
else
{
if(p->next==null)
{ while(lp->num!=0)
{
sum+=p->num-lp->num;
p=lp;
printf(" %d ",p->num);
lp=p->pre;
}
return(sum);
}
if(p->pre==null)
{
while(rp->num!=0)
{
sum+=rp->num-p->num;
p=rp;
printf(" %d ",p->num);
rp=p->next;
}
return(sum);
}
}
}while(p->next!=null||p->pre!=null);
}



SCAN(head,n,m)
struct cidaohao *head;
int n,m;
{struct cidaohao *p,*pp;
int sum=0;
printf("\nSCAN : ");
p=head;
while(p->num!=m) p=p->next;/* */
pp=p;
if(n{while(pp->next!=null)
{
sum+=pp->next->num-pp->num;
pp=pp->next;
printf(" %d ",pp->num);
}
sum+=pp->num-p->pre->num;
pp=p->pre;
if(pp->num==0) return(sum);
else
{while(pp->pre!=null)
{
printf(" %d ",pp->num);
sum+=pp->num-pp->pre->num;
pp=pp->pre;
}
printf(" %d ",pp->num);
return(sum);
}
}
else
{
while(pp->pre!=null)
{
sum+=pp->num-pp->pre->num;
pp=pp->pre;
printf(" %d ",pp->num);
}
sum+=p->next->num-pp->num;
pp=p->next;
if(pp->num==0) return(sum);
else
{while(pp->next!=null)
{
printf(" %d ",pp->num);
sum+=pp->next->num-pp->num;
pp=pp->next;
}
printf(" %d ",pp->num);
return(sum);
}
}
}




main()
{

FILE *fp;
char pt;
char str[10];
int cidao[100],i,j=1,count1=0,count2=0,count3=0,last,space=0;
struct cidaohao *p1,*p2,*new,*head;/* */
struct cidaohao *p,*lp,*rp;
for(i=0;i<50;i++) cidao[i]=-1;
i=0;
fp=fopen("cipan.txt","r+");/* */
if(fp==NULL)
{
printf("Cann't open this file ");
exit(0);
}
printf("\nPlease input cidaohao now : ");
scanf("%d",&cidao[0]);
while((pt=fgetc(fp))!=EOF)/* */
{
if(pt>='0'&&pt<='9')
{
str[i]=pt;i++;
space=0;

}
else
{
if(pt==' '||pt=='\n')
{if(space==1) break;
else
{str[i]='\0';
cidao[j]=atoi(str);
if(pt=='\n') break;
else
{
space=1;
j++;
i=0;
}
}
}
}
}/* */
if(pt==EOF) {str[i]='\0';cidao[j]=atoi(str);}
fclose(fp);
i=0;
count1=FCFS(cidao);/* */
printf("\nThe Total : %d \n",count1);
p1=p2=head=(struct cidaohao* )malloc(len);/* */
p1->pre=null;
p1->num=cidao[0];
p1->next=null;
i=1;
while(cidao[i]!=-1)
{ if(cidao[i]num)/* */
{
p1=(struct cidaohao *)malloc(len);
p1->next=head;
p1->pre=null;
p1->num=cidao[i];
head->pre=p1;
head=p1;
}
else
{
while(p1->next!=null&&p1->num<=cidao[i])/* */
{ p2=p1;
p1=p1->next;
}
if (p1->num>cidao[i])/* */
{
new=(struct cidaohao*)malloc(len);
new->num=cidao[i];
new->next=p1;
new->pre=p2;
p1->pre=new;
p2->next=new;
}
else
{/* */
new=(struct cidaohao*)malloc(len);
new->num=cidao[i];
new->next=null;
new->pre=p1;
p1->next=new;
}
p1=head;/* */
}
i++;/* */
}
count2=SSTF(head,cidao[0]);
printf("\nThe Total : %d ",count2);
printf("\n\nPleast input last cipanhao : ");
scanf("%d",&last);
count3=SCAN(head,last,cidao[0]);
printf("\nThe Total : %d \n",count3);
}