操作系统磁盘调度算法(C++).doc

#include#include#includeusing namespace std;const int MaxNumber=100;int TrackOrderMaxNumber;int MoveDistanceMaxNumber; /-移动距离;int FindOrderMaxNumber; /-寻好序列。double AverageDistance; /-平均寻道长度bool direction; /-方向 true时为向外，false为向里int BeginNum; /-开始磁道号。int M; /-磁道数。int N; /-提出磁盘I/O申请的进程数int SortOrderMaxNumber; /-排序后的序列bool FinishedMaxNumber;void Inith()coutM;coutN;cout请依次输入要访问的磁道号：;for(int i=0;iTrackOrderi;for(int j=0;jN;j+)MoveDistancej=0;coutBeginNum;for(int k=0;kN;k+)Finishedk=false;for(int l=0;l=0;i-)for(int j=0;jSortOrderj+1) temp=SortOrderj; SortOrderj=SortOrderj+1; SortOrderj+1=temp;/=FCFS,先来先服务=void FCFS()int temp;temp=BeginNum; /-将BeginNum赋给temp作为寻道时的当前所在磁道号for(int i=0;iN;i+)MoveDistancei=abs(TrackOrderi-temp); /-计算移动磁道数temp=TrackOrderi; /-寻到后，将此道作为当前所在磁道号，赋给tempFindOrderi=TrackOrderi; /-寻好的赋给寻好序列/=SSTF,最短寻道法=void SSTF()int temp,n;int A=M;temp=BeginNum; /-将BeginNum赋给temp作为寻道时的当前所在磁道号for(int i=0;iN;i+)for(int j=0;jN;j+) /-寻找最短的寻道长度if(abs(TrackOrderj-temp)A&Finishedj=false)A=abs(TrackOrderj-temp);n=j;else continue;Finishedn=true; /-将已经寻找到的Finished赋值为trueMoveDistancei=A; /-寻道长度temp=TrackOrdern; /-当前寻道号。A=M; /-重置A值FindOrderi=TrackOrdern; /-寻好的赋给寻好序列/=SCAN,扫描算法=void SCAN()int m,n,temp;temp=BeginNum;Sort(); /-排序coutm;if(m=1)direction=true;else if(m=0)direction=false;elsecout输入错误;for(int i=0;iN;i+)if(SortOrderiBeginNum)continue;elsen=i;break;if(direction=true) /-选择向外for(int i=n;i=0;j-)MoveDistanceN-1-j=abs(SortOrderj-temp);temp=SortOrderj;FindOrderN-1-j=SortOrderj;else /-选择向里for(int i=n-1;i=0;i-)MoveDistanceN-i-4=abs(SortOrderi-temp);temp=SortOrderi;FindOrderN-i-4=SortOrderi;for(int j=n;jN;j+)MoveDistancej=abs(SortOrderj-temp);temp=TrackOrderj;FindOrderj=SortOrderj;/=CSCAN,循环扫描算法=void CSCAN()int m,n,temp;temp=BeginNum;Sort();coutm;if(m=1)direction=true;else if(m=0)direction=false;elsecout输入错误;for(int i=0;iN;i+)if(SortOrderiBeginNum)continue;elsen=i;break;if(direction=true)for(int i=n;iN;i+)MoveDistancei-n=abs(SortOrderi-temp);temp=SortOrderi;FindOrderi-n=SortOrderi;for(int j=0;j=0;i-)MoveDistancen-1-i=abs(SortOrderi-temp);temp=SortOrderi;FindOrdern-1-i=SortOrderi;for(int j=N-1;j=n;j-)MoveDistanceN-j+n-1=abs(SortOrderj-temp);temp=SortOrderj;FindOrderN-j+n-1=SortOrderj;/=计算平均寻道时间=void Count()int Total=0;for(int i=0;iN;i+)Total+=MoveDistancei;AverageDistance=(double)Total)/(double)N);void Show()cout=从BeginNum号磁道开始=endl;coutsetw(20)被访问的下一个磁道号setw(20)移动距离(磁道数)endl;for(int i=0;iN;i+)coutsetw(15)FindOrderisetw(15)MoveDistanceiendl;coutsetw(20)平均寻道长度:AverageDistanceendl;coutendl;int main()int y=1;int s;Inith();while(y)couts;switch(s) case 1:FCFS();Count();Sh