FCFS,SJF,HRN

1、编写并调试一个单道处理系统的作业等待模拟程序。

　　作业等待算法：分别采用先来先服务（FCFS），最短作业优先（SJF）、响应比高者优先（HRN）的调度算法。

　　对每种调度算法都要求打印每个作业开始运行时刻、完成时刻、周转时间、带权周转时间，以及这组作业的平均周转时间及带权平均周转时间，以比较各种算法的优缺点。

输入样例：

作业名   提交时间   运行时间

1         5         2

2         2         5

3         2         4

FCFS：

按照提交时间排序：2,3,1

作业2 开始时间 2

       运行时间 5

       完成时间 7

       周转时间 7 - 2 = 5

       带权周转时间 5 / 5 = 1

作业 3 开始时间 7

       运行时间 4

       完成时间 11

       周转时间 11 - 2 = 9

       带权周转时间 9 / 4 = 2.25

作业 1 开始时间 11

       运行时间 2

       完成时间 13

       周转时间 13 - 5 = 8

       带权周转时间 8 / 2 = 4

SJF:

按照运行时间从短到长排序：1,3,2

作业 1 开始时间 5

       运行时间 2

       完成时间 7

       周转时间 7 - 5 = 2

       带权周转时间 2 / 2 = 1

作业3 开始时间 7

       运行时间 4

       完成时间 11

       周转时间 11 - 2 = 9

       带权周转时间 9 / 4 = 2.25

作业 2 开始时间 11

       运行时间 5

       完成时间 16

       周转时间 16 - 2 = 14

       带权周转时间 14 / 5 = 2.8

HRN:

作业1 等待时间 5 - 5 = 0  优先权 0 / 2 + 1 = 1

作业2 等待时间 5 - 2 = 3  优先权 3 / 5 + 1 = 1.6

作业3 等待时间 5 - 2 = 3  优先权 3 / 4 + 1 = 1.75

按照优先权排序：3,2,1

作业 3 开始时间 2

       运行时间 4

       完成时间 6

       周转时间 6 - 2 = 4

       带权周转时间 4 / 4 = 1

作业 2 开始时间 6

       运行时间 5

       完成时间 11

       周转时间 11 - 2 = 9

       带权周转时间 11 / 5 = 1.8

  作业1 开始时间 11

         运行时间 2

         完成时间 13

         周转时间 13 - 5 = 8

         带权周转时间 8 / 2 = 4

#include <iostream>
#include <cmath>
using namespace std;

struct Box
{
    string ID;                                       //作业号
    double begin_time;                               //提交时间
    double turnaround_time;                          //周转时间
    double service_time;                             //要求服务时间
    double finish_time;                              //完成时间
    double Wturnaround_time;                         //带权周转时间
    double wait_time;                                //等待时间
    double rate;                                     //优先权
    Box& operator = (const Box& p2)                 //重载 = 运算符，方便排序
    {
        this->begin_time = p2.begin_time;
        this->finish_time = p2.finish_time;
        this->service_time = p2.service_time;
        this->ID = p2.ID;
        this->turnaround_time = p2.turnaround_time;
        this->Wturnaround_time = p2.Wturnaround_time;
        this->wait_time = p2.wait_time;
        this->rate = p2.rate;
        return *this;
    }
};

typedef struct
{
    Box data[100];

} JCB;

JCB jcb;
int n;

void init()                                                        //初始化作业块
{
    cout<<"please input the number of the process:";
    cin>>n;
    for(int i = 0; i<n; i++)
    {
        cout<<"process ID:";
        cin>>jcb.data[i].ID;
        cout<<jcb.data[i].ID<<"'s begin time:";
        cin>>jcb.data[i].begin_time;
        cout<<jcb.data[i].ID<<"'s service time:";
        cin>>jcb.data[i].service_time;
    }
    for(int i = 0; i<n-1; i++)                                    //按照提交时间从前到后排序，小的在前
    {
        for(int j = i+1; j<n; j++)
        {
            if(jcb.data[i].begin_time > jcb.data[j].begin_time)
                swap(jcb.data[i],jcb.data[j]);
        }
    }
    for(int i = 0; i<n-1; i++)                                    //提交时间一样，序号小的排前面
    {
        for(int j = i+1; j<n; j++)
        {
            if(jcb.data[i].begin_time == jcb.data[j].begin_time && jcb.data[i].ID > jcb.data[j].ID)
                swap(jcb.data[i],jcb.data[j]);
        }
    }
}

void FCFS()                                                //先来先服务
{
    double bt = jcb.data[0].begin_time;
    double gtt = 0;
    double gwtt = 0;
    double real_begin;
    cout<<"ID     "<<"real begin time  "<<"begin time  "<<"turnaround time  "<<"finish time  "<<"wighted turnaround time"<<endl;
    for(int i = 0; i<n; i++)
    {
        real_begin = bt;                            //真实开始时间
        jcb.data[i].finish_time = real_begin + jcb.data[i].service_time;        //完成时间 = 开始时间 + 服务时间
        jcb.data[i].turnaround_time = jcb.data[i].finish_time - jcb.data[i].begin_time; //周转时间 = 完成时间 - 提交时间
        jcb.data[i].Wturnaround_time = jcb.data[i].turnaround_time/jcb.data[i].service_time; //带权周转时间 = 周转时间/服务时间
        cout<<jcb.data[i].ID<<"             "<<real_begin<<"            "<<jcb.data[i].begin_time
            <<"            "<<jcb.data[i].turnaround_time<<"            "<<jcb.data[i].finish_time
            <<"             "<<jcb.data[i].Wturnaround_time<<endl;
        bt = jcb.data[i].finish_time;                //下一个作业的开始时间
        gtt += jcb.data[i].turnaround_time;          //总周转时间
        gwtt += jcb.data[i].Wturnaround_time;        //总带权周转时间
    }
    cout<<"group's turnaround time :"<<gtt/n<<endl;
    cout<<"group's wighted turnaround time :"<<gwtt/n<<endl;
}

void SJF()                        //短作业优先
{
    double bt = 0;
    double gtt = 0;
    double gwtt = 0;
    double real_begin;
    cout<<"ID     "<<"real begin time  "<<"begin time  "<<"turnaround time  "<<"finish time  "<<"wighted turnaround time"<<endl;
    for(int i = 0; i<n-1; i++)                        //按照服务时间从小到大排序
        for(int j = i; j<n; j++)
            if(jcb.data[i].service_time > jcb.data[j].service_time)
                swap(jcb.data[i],jcb.data[j]);
    for(int i = 0; i<n-1; i++)
    {
        for(int j = i+1; j<n; j++)
        {
            if(jcb.data[i].service_time == jcb.data[j].service_time && jcb.data[i].ID > jcb.data[j].ID)
                swap(jcb.data[i],jcb.data[j]);
        }
    }
    bt = jcb.data[0].begin_time;
    for(int i = 0; i<n; i++)
    {
        real_begin = bt;
        jcb.data[i].finish_time = real_begin + jcb.data[i].service_time;
        jcb.data[i].turnaround_time = jcb.data[i].finish_time - jcb.data[i].begin_time;
        jcb.data[i].Wturnaround_time = jcb.data[i].turnaround_time/jcb.data[i].service_time;
        cout<<jcb.data[i].ID<<"                 "<<real_begin<<"            "<<jcb.data[i].begin_time
            <<"            "<<jcb.data[i].turnaround_time<<"            "<<jcb.data[i].finish_time
            <<"             "<<jcb.data[i].Wturnaround_time<<endl;
        bt = jcb.data[i].finish_time;
        gtt += jcb.data[i].turnaround_time;
        gwtt += jcb.data[i].Wturnaround_time;
    }
    cout<<"group's turnaround time :"<<gtt/n<<endl;
    cout<<"group's wighted turnaround time :"<<gwtt/n<<endl;
}

void HRN()                     //高响应比优先
{
    double bt = 0;
    double gtt = 0;
    double gwtt = 0;
    double real_begin;
    cout<<"ID     "<<"real begin time  "<<"begin time  "<<"turnaround time  "<<"finish time  "<<"wighted turnaround time"<<endl;
    for(int i = 0; i<n; i++)
    {
        jcb.data[i].wait_time = jcb.data[n-1].begin_time - jcb.data[i].begin_time; //等待时间 = 作业最后提交时间 - 提交时间
        jcb.data[i].rate = jcb.data[i].wait_time/jcb.data[i].service_time+1;      //高响应比 = 等待时间 / 服务时间 + 1
    }
    for(int i = 0; i<n-1; i++)
        for(int j = i; j<n; j++)
            if(jcb.data[i].rate < jcb.data[j].rate)
                swap(jcb.data[i],jcb.data[j]);
    bt = jcb.data[0].begin_time;
    for(int i = 0; i<n; i++)
    {
        real_begin = bt;
        jcb.data[i].finish_time = real_begin + jcb.data[i].service_time;
        jcb.data[i].turnaround_time = jcb.data[i].finish_time - jcb.data[i].begin_time;
        jcb.data[i].Wturnaround_time = jcb.data[i].turnaround_time/jcb.data[i].service_time;
        cout<<jcb.data[i].ID<<"             "<<real_begin<<"            "<<jcb.data[i].begin_time
            <<"            "<<jcb.data[i].turnaround_time<<"            "<<jcb.data[i].finish_time
            <<"             "<<jcb.data[i].Wturnaround_time<<endl;
        bt = jcb.data[i].finish_time;
        gtt += jcb.data[i].turnaround_time;
        gwtt += jcb.data[i].Wturnaround_time;
    }
    cout<<"group's turnaround time :"<<gtt/n<<endl;
    cout<<"group's wighted turnaround time :"<<gwtt/n<<endl;
}

int main()
{
    int k = 0;
    while(1)
    {
        cout<<"*****************************"<<endl;
        cout<<"         1.FCFS"<<endl<<"         2.SJF"<<endl<<"         3.HRN"<<endl;
        cout<<"*****************************"<<endl;
        cout<<"please choose:";
        cin>>k;
        init();
        switch(k)
        {
        case 1:
            FCFS();
            break;
        case 2:
            SJF();
            break;
        case 3:
            HRN();
            break;
        default:
            break;
        }
    }
    return 0;
}