1、电梯优先调度算法电梯调度算法(ms InterView) 移臂调度算法包括以下四种：1） 先来先服务算法：根据访问者提出访问请求的先后次序来决定执行次序。2） 最短寻找时间优先调度算法：从等待的访问者中挑选寻找时间最短的那个请求执行，而不管访问者的先后次序。3） 电梯调度扫描算法：从移动臂当前位置沿移动方向选择最近的那个柱面的访问者来执行，若该方向上无请求访问时，就改变移动方向再选择。4） 单向扫描调度算法：从 0 柱面开始往里单向扫描，扫到哪个执行哪个。*/ / t1.cpp : 定义控制台应用程序的入口点。 / #include stdafx.h #includemath.h #inclu
2、destdlib.h #includestring.h struct Head int nPosition; bool bVisited; ; void Visit(struct Head *pHead) printf(visite cy:%dn,pHead-nPosition); pHead-bVisited=true; int ReadInputKeyboard(struct Head *pHead,int *pCurrentPosition,int nMaxNumber) int i; printf(please input Current position:); scanf(%d,pC
3、urrentPosition); printf(please input will visit position:); for(i=0;inMaxNumber;i+) scanf(%d,pHeadi.nPosition); pHeadi.bVisited=false; if(pHeadi.nPosition0) break; return i; int ReadInputFile(struct Head *pHead,int *pCurrentPosition,int nMaxNumber) int i; char szFileName256,*q,*p,szTemp20; printf(pl
4、ease input filename:); scanf(%s,szFileName); FILE *pFile=fopen(szFileName,r); if(pFile=NULL) printf(open file %s error,szFileName); return -1; for(i=0;!feof(pFile) inMaxNumber;) p=szFileName; fgets(p,256,pFile); while(q=strchr(p,) memset(szTemp,0,sizeof(szTemp)*sizeof(char); strncpy(szTemp,p,q-p); p
5、=q+1; if(i=0) *pCurrentPosition=atoi(szTemp); else pHeadi-1.nPosition=atoi(szTemp); pHeadi-1.bVisited=false; i+; memset(szTemp,0,sizeof(szTemp)*sizeof(char); pHeadi-1.nPosition=atoi(p); pHeadi-1.bVisited=false; /i+; fclose(pFile); return i; int FifoVisit(int nCurrentPosition,struct Head *pHead,int n
6、Number) /先来先服务 int nHaveVisited=0; int nMoveDistance=0; int i; while(nHaveVisitednNumber) for(i=0;inNumber;i+) if(pHeadi.bVisited) continue; Visit(pHeadi); nHaveVisited+; nMoveDistance+=abs(nCurrentPosition-pHeadi.nPosition); nCurrentPosition=pHeadi.nPosition; printf(the sum of move distance:%dn,nMo
7、veDistance); return nMoveDistance; int SsfoVisit(int nCurrentPosition,struct Head *pHead,int nNumber) / 最短寻找时间优先 int nHaveVisited=0; int nMoveDistance=0; int nMinDistance=0; int nMinIndex=0; int i; while(nHaveVisitednNumber) nMinDistance=0xffff; nMinIndex=0; /找最小值 for(i=0;inNumber;i+) if(pHeadi.bVis
8、ited) continue; if(nMinDistanceabs(pHeadi.nPosition-nCurrentPosition) nMinDistance=abs(pHeadi.nPosition-nCurrentPosition); nMinIndex=i; /访问 Visit(pHeadnMinIndex); nHaveVisited+; nMoveDistance+=nMinDistance; nCurrentPosition=pHeadnMinIndex.nPosition; printf(the sum of move distance:%dn,nMoveDistance)
9、; return nMoveDistance; int DtVisit(int nCurrentPosition,bool bOut,struct Head *pHead,int nNumber) /电梯调度算法 int nHaveVisited=0; int nMoveDistance=0; int nMinDistance=0; int nMinIndex=0; int i; while(nHaveVisitednNumber) nMinDistance=0xffff; nMinIndex=0; /找最小值 for(i=0;inNumber;i+) if(pHeadi.bVisited)
10、continue; if(bOutpHeadi.nPositionnCurrentPosition|!bOutpHeadi.nPositionnCurrentPosition) if(nMinDistanceabs(pHeadi.nPosition-nCurrentPosition) nMinDistance=abs(pHeadi.nPosition-nCurrentPosition); nMinIndex=i; if(nMinDistance=0xffff) bOut=!bOut; continue; /访问 Visit(pHeadnMinIndex); nHaveVisited+; nMo
11、veDistance+=nMinDistance; nCurrentPosition=pHeadnMinIndex.nPosition; printf(the sum of move distance:%dn,nMoveDistance); return nMoveDistance; int DxVisit(int nCurrentPosition,struct Head *pHead,int nNumber) /单向调度算法 int nHaveVisited=0; int nMoveDistance=0; int nMinDistance=0; int nMinIndex=0; int i;
12、 while(nHaveVisitednNumber) nMinDistance=0xffff; nMinIndex=0; /找最小值 for(i=0;inNumber;i+) if(pHeadi.bVisited) continue; if(pHeadi.nPositionnCurrentPosition ) if(nMinDistanceabs(pHeadi.nPosition-nCurrentPosition) nMinDistance=abs(pHeadi.nPosition-nCurrentPosition); nMinIndex=i; if(nMinDistance=0xffff)
13、 nMoveDistance+=199-nCurrentPosition; nCurrentPosition=0; continue; /访问 Visit(pHeadnMinIndex); nHaveVisited+; nMoveDistance+=nMinDistance; nCurrentPosition=pHeadnMinIndex.nPosition; printf(the sum of move distance:%dn,nMoveDistance); return nMoveDistance; int main(int argc, char* argv) /p114 struct
14、Head mylist20;/=98,false,183,false,37,false,122,false,14,false,124,false,65,false,67,false; /int nCurrentPosition=53; /int nRealNumber=8; int nCurrentPosition=0; int nRealNumber=ReadInputFile(mylist,nCurrentPosition,20); / FifoVisit(nCurrentPosition,mylist,nRealNumber); / SsfoVisit(nCurrentPosition,mylist,nRealNumber); /DtVisit(nCurrentPosition,false,mylist,nRealNumber); DxVisit(nCurrentPosition,mylist,nRealNumber); return 0;
