原理：
按照作业进入系统的先后次序来挑选作业，先进入系统的作业优先被挑选。 用c语言写的，采用单链表来模拟PCB,实现CPU调用进程。
FcFs.h:
#define _CRT_SECURE_NO_WARNINGS
#include
#includetypedef struct PCB
{
char ID[15];
//进程名字
int arrive_time;
//进程到达时间
int work_time;
//进程服务时间
int start_time;
//进程开始时间
int finish_time;
//进程完成时间
int turnover_time;
//周转时间
double Wturnover_time;
//加权周转时间
int data;
//执行顺序
char sign;
//标记 N 表示已排序,不能进入。Y表示没排序，可以进入。
struct PCB *next;
}PCB,*P_PCB;
//接收所有进程，形成PCB链表
int Enter(P_PCB start)
{
int process_sum = 0;
//进程的总数
printf("请输入进程的个数：");
scanf("%d", &process_sum);
start->data = https://www.it610.com/article/process_sum;
//头指针装入了进程总数 for (int i = 0;
i < process_sum;
i++)
{
//录入第i个进程的信息
P_PCB newHead;
newHead = (P_PCB)malloc(sizeof(PCB));
//新的节点
printf("请输入进程%d的名字:", i+1);
scanf("%s", newHead->ID);
printf("请输入进程%d的到达时间；", i+1);
scanf("%d", &newHead->arrive_time);
printf("请输入进程%d的服务时间；", i+1);
scanf("%d", &newHead->work_time);
system("cls");
newHead->next = start->next;
start->next = newHead;
}
return 0;
}//根据进程到达时间对除ID和arrive_time和work_time外其他值赋值
int Rank(P_PCB start)
{
int temp, atime, ftime;
P_PCB m= NULL,p,q;
//p为了找一个sign是Y的节点把arrive_time给temp，q是和其他的arrive_time比较的跟踪节点，m是最小temp的跟踪
//对所有节点的sign赋值
p = start->next;
for(int i=0;
idata;
i++)
{
p->sign = 'Y';
p = p->next;
}
//给每一个节点赋了 data值
for (int i=0;
i< start->data ;
i++)
{
//arrive_time找最小值
p = start->next;
while (p->next != NULL)
{
if (p->sign == 'Y')
{
temp = p->arrive_time;
m = p;
break;
}
}
q = p;
while ( q->next != NULL)
{
q = q->next;
if (q->sign == 'Y'&& temp > q->arrive_time)
{
temp = q->arrive_time;
m = q;
}
}
m->data = https://www.it610.com/article/i + 1;
m->sign = 'N';
//根据data值对start_time和finish_time和sign赋值
if (m->data =https://www.it610.com/article/= 1)
{
m->start_time = m->arrive_time;
//开始时间
m->finish_time = m->work_time;
//结束时间
atime = m->start_time;
ftime = m->finish_time;
m->turnover_time = m->finish_time - m->arrive_time;
//周转时间(完成-到达)
m->Wturnover_time = (double)m->turnover_time / m->work_time;
//加权周转时间
}
else
{
if (m->arrive_time <= ftime)
{
m->start_time = ftime;
//开始时间
m->finish_time = m->work_time+ m->start_time;
//结束时间
atime = m->start_time;
ftime = m->finish_time;
m->turnover_time = m->finish_time - m->arrive_time;
//周转时间(完成-到达)
m->Wturnover_time = (double)m->turnover_time / m->work_time;
//加权周转时间
}
else
{
m->start_time= m->arrive_time;
//开始时间
m->finish_time = m->work_time+ m->start_time;
//结束时间
atime = m->start_time;
ftime = m->finish_time;
m->turnover_time = m->finish_time - m->arrive_time;
//周转时间(完成-到达)
m->Wturnover_time = (double)m->turnover_time / m->work_time;
//加权周转时间
}
}
}
return 0;
}//输出所有进程信息
void A(P_PCB start)
{
P_PCB p ;
for (int i = 0;
i < start->data;
i++)
{
p = start;
while (p->next!= NULL)
{
p = p->next;
if (p->data =https://www.it610.com/article/= i + 1)
{
printf("进程名字%s,到达时间:%d,服务时间:%d", p->ID, p->arrive_time, p->work_time);
printf("开始时间:%d ,完成时间:%d ,周转时间:%d ,加权周转时间:%lf\n", p->start_time, p->finish_time, p->turnover_time, p->Wturnover_time);
printf("+++++++++++++++++++++++++++++++\n");
}
}
}
}//模拟cpu运行
void B(P_PCB start)
{
P_PCB q;
for (int m = 0;
m < start->data;
m++)
{
q = start;
for (int i = 0;
i < start->data;
i++)
{
q = q->next;
if (q->data =https://www.it610.com/article/= m + 1)
{
printf("在%d时刻：%s进程开始执行。\n", q->start_time, q->ID);
for (int j = q->start_time;
j <= q->finish_time;
j++)
{
printf("在%d时刻：%s进程正在执行。\n", j, q->ID);
}
printf("在%d时刻：%s进程结束执行。\n", q->finish_time, q->ID);
break;
}
}
}
}//函数调用
int Show(P_PCB start)
{
int a = 0;
P_PCB p = start;
printf("请录入进程的信息：\n");
Enter(start);
Rank(start);
while (1)
{
printf("请选择你要展示的效果：\n");
printf("1.输出所有进程的信息。\n");
printf("2.模拟cpu工作状态。\n");
printf("3.退出.\n");
scanf("%d", &a);
switch (a)
{
case 1: A(start);
break;
case 2: B(start);
break;
case 3: exit(0);
break;
default:break;
}
system("pause");
system("cls");
}
return 0;
}FcFs_test.cpp:
#include"FcFs.h"int main()
{
P_PCB start;
start = (P_PCB)malloc(sizeof(PCB));
//头结点
start->next = NULL;
Show(start);
return 0;
}【FCFS算法】
