// 时间片轮转调度算法#include <iostream>#include <cstdio>#include <cmath>#include <cstring>using namespace std;enum STATUS {RUN,READY,WAIT,FINISH};struct PCBNode{int processID; //进程IDSTATUS status; //进程状态int priorityNum; //优先数int reqTime; //总的需要运行时间int remainTime; //剩下需要运行时间int arriveTime; //进入就绪队列时间int startTime; //开始运行时间int finishTime; //结束运行时间int totalTime; //周转时间float weightTotalTime; //带权周转时间};struct QueueNode{int ID; //进程IDstruct QueueNode * next; //队列中下一个进程指针};struct LinkQueue{QueueNode *head;//队首};void Fcfs(LinkQueue& Q, int& totalTimeSum, int& weightTotalTimeSum,PCBNod e * ProcessT able);bool RR_Run(LinkQueue& Q,QueueNode* q, QueueNode* p, const int Roun d,int& currentTime,PCBNode * ProcessT able);//分配时间片给q所指进程,p为刚退出的进程void RoundRobin(LinkQueue& Q,const int Round, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessT able);//时间片轮转调度,调用RR_Run(),时间片大小设为Roundvoid InitialQueue(LinkQueue& Q,PCBNode * ProcessT able,const int processnum );//初始化就绪队列void Input(PCBNode * ProcessT able, const int processnum);//从input.txt文件输入数据int main(){LinkQueue Q;//就绪队列Q.head = NULL;const int processnum = 16;//进程数const int Round = 1; //时间片大小int totalTimeSum = 0; //周转时间int WeightTotalTimeSum = 0;//带权周转时间PCBNode * ProcessT able=new PCBNode[processnum]; //进程表Input(ProcessT able, processnum);InitialQueue(Q, ProcessT able, processnum);RoundRobin(Q, Round, totalTimeSum,WeightTotalTimeSum,ProcessT able);cout < < "时间片轮调度的平均周转时间为: " < <totalTimeSum/processnum < <endl;cout < < "时间片轮调度的平均带权周转时间为: " < <WeightTotalTimeSum/processnum < <endl;Input(ProcessT able, processnum);InitialQueue(Q, ProcessT able, processnum);Fcfs(Q, totalTimeSum,WeightTotalTimeSum,ProcessT able);cout < < "先来先服务的平均周转时间为: " < <totalTimeSum/processnum < <endl;cout < < "先来先服务的平均带权周转时间为: " < <WeightTotalTimeSum/processnum < <endl;delete [] ProcessT able;return 0;}void RoundRobin(LinkQueue& Q,const int Round, int& totalTimeSum, int& weightTotalTimeSum,PCBNode * ProcessT able){totalTimeSum = 0; //总的周转时间weightTotalTimeSum = 0;//平均周转时间int currentTime = 0; //当前时间QueueNode* p;QueueNode* q;QueueNode* r;bool finish = false;//调用RR_Run()后,该进程是否已经做完退出p = Q.head;q = p-> next;while (q != NULL)//从队首开始依次分配时间片{do{cout < < "********************** " < <endl;cout < < "在时间片" < <(currentTime+1)/Round < < "内,活动进程为: " < <q-> ID < <endl;cout < < "进程" < <q-> ID < < " 现在需要的时间片为: " < <ProcessT able[q-> ID].remainTime < <endl;finish = RR_Run(Q, q, p, Round, currentTime, ProcessT a ble);//分配时间片给q进程cout < <endl;if (!finish)//若是进程在本时间片内做完,则跳出d o…while循环{if (q-> next == NULL){r = Q.head-> next;}else{r = q-> next;}}else //否则计算周转时间和带权周转时间{totalTimeSum += ProcessT able[q-> ID].totalTime;weightTotalTimeSum += ProcessT able[q-> ID].weightTotalTime;delete q; //从队列中删除q进程q = p;}}while (!finish && (ProcessT able[r-> ID].arriveTime > currentTime + Round));//下一个进程很晚才来,则继续给当前进程分配时间片p = q;q = q-> next;if (q == NULL && Q.head-> next!=NULL){p = Q.head;q = p-> next;}}delete Q.head;Q.head = NULL;}bool RR_Run(LinkQueue& Q,QueueNode* q, QueueNode* p, const int Roun d,int& currentTime,PCBNode * ProcessT able){if (ProcessT able[q-> ID].remainTime <= Round)//在此时间片内能够做完,之后退出进程调度{ProcessT able[q-> ID].finishTime = currentTime + ProcessT able[q-> ID].remainTime;ProcessT able[q-> ID].totalTime += ProcessT able[q-> ID].remainTime;ProcessT able[q-> ID].weightTotalTime = ProcessT able[q-> ID].totalTime/ProcessT able[q-> ID].reqTime;currentTime = ProcessT able[q-> ID].finishTime;p-> next = q-> next;cout < <endl;cout < < "进程" < <q-> ID < < "完成! " < <endl;return true;}else//此时间片内做不完{ProcessT able[q-> ID].remainTime = ProcessT able[q-> ID].remainTime - Round;ProcessT able[q-> ID].totalTime += Round;currentTime += Round;return false;}}void Fcfs(LinkQueue& Q, int& totalTimeSum, int& weightTotalTimeSum,PCBNod e * ProcessT able){totalTimeSum = 0;weightTotalTimeSum = 0;//平均周转时间QueueNode* p;QueueNode* q;p = Q.head-> next;if (p !=NULL ){ProcessT able[p-> ID].startTime = ProcessT able[p-> ID].arriveTime;ProcessT able[p-> ID].finishTime = ProcessT able[p-> ID].arriveTime + ProcessT able[p-> ID].reqTime;}for(q=p-> next; q!=NULL; q=q-> next){if (ProcessT able[q-> ID].arriveTime < ProcessT able[p-> ID].finishTime){ProcessT able[q-> ID].startTime = ProcessT able[p-> ID].finishTime;ProcessT able[q-> ID].finishTime = ProcessT able[p-> ID].finishTime + ProcessT able[q-> ID].reqTime;}else//下个进程到达时间较晚{ProcessT able[q-> ID].startTime = ProcessT able[q-> ID].arriveTime;ProcessT able[q-> ID].finishTime = ProcessT able[q-> ID].arriveTime + ProcessT able[q-> ID].reqTime;}p = q;}for(q=Q.head-> next; q!=NULL; q=q-> next){ProcessT able[q-> ID].totalTime = ProcessT able[q-> ID].finishTime - ProcessT able[q-> ID].arriveTime;ProcessT able[q-> ID].weightTotalTime = ProcessT able[q-> ID].totalTime/ProcessT able[q-> ID].reqTime;totalTimeSum += ProcessT able[q-> ID].totalTime;weightTotalTimeSum += ProcessT able[q-> ID].weightTotalTime;}int t = 0;for(q=Q.head-> next; q!=NULL; q=q-> next){cout < < "********************* " < <endl;while ( t <ProcessT able[q-> ID].finishTime ){cout < < "时刻" < <t < < ": 进程" < <q-> ID < < "活动" < <endl;t++;}if (q-> next != NULL){cout < < "时刻" < <t < < ": 进程" < <q-> ID < < "结束活动,开始下一个进程. " < <endl;cout < < "进程" < <q-> ID < < "的周转时间为: " < <ProcessT able[q-> ID].totalTime < <endl;cout < < "进程" < <q-> ID < < "的带权周转时间为: " < <ProcessT able[q-> ID].weightTotalTime < <endl < <endl;}else{cout < < "时刻" < <t < < ": 进程" < <q-> ID < < "结束活动. " < <endl < <endl;cout < < "进程" < <q-> ID < < "的周转时间为: " < <ProcessT able[q-> ID].totalTime < <endl;cout < < "进程" < <q-> ID < < "的带权周转时间为: " < <ProcessT able[q-> ID].weightTotalTime < <endl < <endl;}}cout < < "所有进程结束活动. " < <endl < <endl;p = Q.head;for(q=p-> next; q!=NULL; q=q-> next){delete p;p = q;}}void InitialQueue(LinkQueue& Q, PCBNode * ProcessT able,const int processn um){//初始化for (int i=0;i <processnum;i++){ProcessT able[i].processID=i;ProcessT able[i].reqTime=ProcessT able[i].remainTime;ProcessT able[i].finishTime=0;ProcessT able[i].startTime=0;ProcessT able[i].status=WAIT;ProcessT able[i].totalTime=0;ProcessT able[i].weightTotalTime=0;}Q.head = new QueueNode;Q.head-> next = NULL;QueueNode * p;QueueNode * q;for (i=0;i <processnum;i++){p = new QueueNode;p-> ID = i;p-> next = NULL;if (i == 0){Q.head-> next = p;}elseq-> next = p;q = p;}}void Input(PCBNode * ProcessT able, const int processnum){FILE *fp; //读入线程的相关内容if((fp=fopen( "input.txt ", "r "))==NULL){cout < < "can not open file! " < <endl;exit(0);}for(int i=0;i <processnum;i++){fscanf(fp, "%d %d %d ",&ProcessT able[i].arriveTime,&ProcessT able[i].remainTime,&ProcessT able[i].priorityNum);}fclose(fp);}建议输入数据:input.txt0 4 01 35 12 10 23 5 36 9 47 21 5 9 35 611 23 712 42 813 1 914 7 10 20 5 1123 3 1224 22 1325 31 1426 1 15。