//大神帮看看哪有错,怎么改,谢谢了!
#include
#include
#define NULL 0
int s=1;
struct PCB{
char p_name[20];
int arrivetime;
int p_needTime;
int p_runTime;
char p_state;
struct PCB* next;
};
void RoundRobin();
char Choice();
int main()
{
char choice = Choice();
switch(choice)
{
case '1':
system("cls");
RoundRobin();
break;
case '2':
return 0;
break;
default:
break;
}
system("pause");
return 0;
}
char Choice()
{
printf("\n\n");
printf(" ********************************************* \n");
printf(" 进程调度演示\n");
printf(" ********************************************* \n\n\n");
printf(" 1.演示轮转法算法.\n");
printf(" 2.退出程序.\n\n");
printf(" 选择进程调度方法:");
char ch = getchar();
return ch;
system("cls");
}
//轮转算法
void RoundRobin()
{
int N,TIME;
printf("请指明时间片大小:");
scanf("%d",&N);
int n;
struct PCB processes, *pt,*min,*q,*de,*z,*x;
processes = pt = min=q=de=(struct PCB)malloc(sizeof(struct PCB));
struct PCB p,*ptem;
ptem=p=z=x=(struct PCB)malloc(sizeof(struct PCB));
z=pt;
x=q;
printf("请输入需要运行进程数:");
scanf("%d",&n);
for (int i = 0; i<n; ++i)//输入队列
{
printf("输入进程名:");
scanf("%s", &p->p_name);
printf("输入进程运行时间:");
scanf("%d", &p->p_needTime);
printf("请输入到达时间:");
scanf("%d,&p->arrivetime");
p->p_runTime = p->p_needTime;
p->p_state = 'W';
z->next=p;
z=z->next;
printf("\n");
}
z->next=NULL;
z=pt->next;
for(i=1;i<n;i++)//排成有序队列
{
min=z;
while(z->next!=NULL)//选出输入队列最早到达的·
{
if(min->arrivetime>z->next->arrivetime)
{
min=z->next;
p=z;
}
z=z->next;
}
z=p;
z->next=min->next;
x->next=min;//插入有序队列
x=x->next;
}
z=pt->next;
x->next=z;
x=x->next;
x->next=NULL;
x=q->next;
q->next=x->next;
processes->next=x;
de=processes->next;
de->next=NULL;
TIME=x->arrivetime;
int cases = 0;
while (s)//开始运算队列
{
if(de==NULL)
{
printf("进程全部结束!");
s=0;
continue;
}
++cases;
printf("第%d轮: \n", cases);
printf("**** 当前正在运行的进程是:%s\n", de->p_name);
de->p_state = 'R';
if(de->p_runTime<=N)
{
TIME=TIME+de->p_runTime;
de->p_state='f';
de->p_runTime=0;
}
else
{
TIME=TIME+N;
de->p_runTime-=N;
}
printf("进程名 状态 共需时间 还需时间\n");
printf("%s\t%c\t%d\t%d\t\n\n", de->p_name, de->p_state, de->p_needTime, de->p_runTime);
printf("**** 当前就绪状态的队列为:\n\n");
while (de->next != NULL)
{
de=de->next;
printf("进程名 状态 共需时间 还需时间\n");
printf("%s\t%c\t%d\t%d\t\n\n", de->p_name, de->p_state, de->p_needTime, de->p_runTime);
}
ptem=de;//最后一个进程用ptem表示
de=processes->next;
if(de->p_state =='f')//删除状态为f的进程
{
processes->next=de->next;
de=processes->next;
}
else//将执行过的进程插到队尾
{
de->p_state='w';
processes->next=de->next;
ptem->next=de;
ptem=ptem->next;
ptem->next=NULL;
}
while(q->next!=NULL&&q->next->arrivetime<TIME)//从序列队列中找出适合的插到执行队列
{
x=q->next;
q->next=x->next;
ptem->next=x;
ptem=ptem->next;
ptem->next=NULL;
}
while(de==NULL&&q->next!=NULL)
{
x=q->next;
q->next=x->next;
ptem->next=x;
ptem=ptem->next;
ptem->next=NULL;
}
de=processes->next;
}
}