SJF.rar_操作系统_短作业优先算法

#include "stdafx.h" #include <iostream> #include <string> using namespace std; struct JOB//作业结构体 { string name; //进程名 float arrivetime;//到达时间 float servicestime;//服务时间 float starttime; //开始时间 float finishtime;//完成时间 float zztime; //周转时间 float dqzztime; //带权周转时间 int sfzx;//是否执行标志位 1已执行 0未执行 }; //获取下一个要执行的工作的服务时间 string search_min(JOB job[], int nowtime) { //记录符合条件的作业的服务时间 JOB job_servicetime[6]; //给服务时间数组赋值 for (int n = 0; n<5; n++) { //符合条件的话赋值 if (job[n].arrivetime <= nowtime && job[n].sfzx == 0) { job_servicetime[n].servicestime = job[n].servicestime; job_servicetime[n].name = job[n].name; } //不符合条件赋-1 else { job_servicetime[n].servicestime = -1; job_servicetime[n].name = " "; } } //声明第三个变量，获取最小服务时间用 int temp_time; string temp_name; //符合条件的作业的服务时间从小到大排序 for (int i = 0; i<5; i++) { for (int j = i + 1; j<5; j++) { //去掉不符合条件的作业 if (job_servicetime[i].servicestime != -1) { if (job_servicetime[i].servicestime>job_servicetime[j].servicestime) { temp_time = job_servicetime[i].servicestime; temp_name = job_servicetime[i].name; job_servicetime[i].servicestime = job_servicetime[j].servicestime; job_servicetime[i].name = job_servicetime[j].name; job_servicetime[j].servicestime = temp_time; job_servicetime[j].name = temp_name; } } } } string name; //最小服务时间赋给num变量 for (int k = 0; k<5; k++) { //去掉不符合条件的作业 if (job_servicetime[k].servicestime != -1) { //num=job_servicetime[k].servicestime; name = job_servicetime[k].name; break; } } //返回num return name; } int input()//输入作业信息函数 { //输入操作 //只记录三个字段的结构体 JOB job_th[6]; //循环输入操作 for (int q = 0; q<5; q++) { cout << "请输入作业名，到达时间，运行时间："; cin >> job_th[q].name >> job_th[q].arrivetime >> job_th[q].servicestime; //标志是否已经执行 job_th[q].sfzx = 0; } JOB job_si[6];//记录七个字段的结构体 //sfzx字段初值为0（表示未执行） for (int s = 0; s<5; s++) { job_si[s].sfzx = 0; } //给第一个作业赋值 job_si[0].name = job_th[0].name; job_si[0].arrivetime = job_th[0].arrivetime; job_si[0].servicestime = job_th[0].servicestime; job_si[0].starttime = job_si[0].arrivetime; job_si[0].finishtime = job_si[0].arrivetime + job_si[0].servicestime; job_si[0].zztime = job_si[0].finishtime - job_si[0].arrivetime; job_si[0].dqzztime = job_si[0].zztime / job_si[0].servicestime; job_si[0].sfzx = 1;//更新执行状态 job_th[0].sfzx = 1;//更新执行状态 //记录job_si结构体的成员数量 int index = 0; //算法核心部分 for (int g = 1; g<5; g++) { //获取下一个工作名称 string name = search_min(job_th, job_si[index].finishtime); //按工作名称计算相关值 for (int f = 1; f<5; f++) { if (job_th[f].name == name) { index = index + 1; job_si[index].name = job_th[f].name; job_si[index].arrivetime = job_th[f].arrivetime; job_si[index].servicestime = job_th[f].servicestime; job_si[index].starttime = job_si[index - 1].finishtime; job_si[index].finishtime = job_si[index].starttime + job_si[index].servicestime; job_si[index].zztime = job_si[index].finishtime - job_si[index].arrivetime; job_si[index].dqzztime = job_si[index].zztime / job_si[index].servicestime; job_si[index].sfzx = 1; job_th[f].sfzx = 1; break; } } } //按执行顺序输出工作 cout.width(9); cout << "作业名"; cout.width(9); cout << "到达时间"; cout.width(11); cout << "服务时间"; cout.width(13); cout << "开始执行时间"; cout.width(10); cout << "完成时间"; cout.width(10); cout << "周转时间"; cout.width(9); cout << "带权周转时间" << endl; for (int i = 0; i<5; i++) { cout.width(9); cout << job_si[i].name; cout.width(9); cout << job_si[i].arrivetime; cout.width(11); cout << job_si[i].servicestime; cout.width(13); cout << job_si[i].starttime; cout.width(10); cout << job_si[i].finishtime; cout.width(10); cout << job_si[i].zztime; cout.width(9); cout << job_si[i].dqzztime << endl�