模拟操作系统最先 最佳 最坏 内存分配算法.doc

模拟操作系统最先最佳最坏内存分配算法(2008-04-17 03:32:37) 转载标签： 杂谈 #include#include#include#includeusing namespace std;const int MAXJOB=10;/定义表最大记录数typedef struct nodeint start; /起始地址int length; /长度char tag20;job;job freesMAXJOB;/定义空闲区表int free_quantity;job occupysMAXJOB;/定义已分配区表int occupy_quantity;/初始化函数void initial()int i;for(i=0;iMAXJOB;i+)freesi.start=-1;freesi.length=0;strcpy(freesi.tag,free);occupysi.start=-1;occupysi.length=0;strcpy(occupysi.tag,);free_quantity=0;occupy_quantity=0;/读数据函数int readData()FILE *fp;char fname20;coutfname;if(fp=fopen(fname,r)=NULL)cout错误,文件打不开,请检查文件名endl;system(pause);elsewhile(!feof(fp)fscanf(fp,%d %d,&freesfree_quantity.start,&freesfree_quantity.length);free_quantity+;free_quantity-;/去掉return 1;return 0;/按起位置排序void sort()int i,j,p;for(i=0;ifree_quantity-1;i+)p=i;for(j=i+1;jfree_quantity;j+) if(freesj.startfreesp.start) p=j; if(p!=i)freesfree_quantity=freesi;freesi=freesp;freesp=freesfree_quantity;/显示函数void view()int i;coutendl-endl;cout当前空闲表:endl;cout起始地址 长度 状态endl;for(i=0;ifree_quantity;i+)coutfreesi.start;cout ;coutfreesi.length;cout ;coutfreesi.tagendl;coutendl-endl;coutendl-endl;coutendl-endl;cout当前已分配表:endl;cout起始地址 长度 占用作业名endl;for(i=0;ioccupy_quantity;i+)coutoccupysi.start;cout ;coutoccupysi.length;cout ;coutoccupysi.tagendl;/最先适应分配算法void earliest()char job_name20;int job_length;int i,j,flag,t;coutjob_name;cinjob_length;flag=0;for(i=0;i=job_length) flag=1;if(flag=0)coutendlSorry,当前没有能满足你申请长度的空闲内存,请稍候再试=job_length)t=1;i+;i-;occupysoccupy_quantity.start=freesi.start;strcpy(occupysoccupy_quantity.tag,job_name);occupysoccupy_quantity.length=job_length;occupy_quantity+;if(freesi.lengthjob_length)freesi.start+=job_length;freesi.length-=job_length;elsefor(j=i;jfree_quantity-1;j+)freesj=freesj+1;free_quantity-;cout内存空间成功:)endl;cout内存空间成功:)endl;cout内存空间成功:)endl;void BadMethod()char job_name20; /名字int job_length; /长度int i,j;int max;coutjob_name;cinjob_length;for(i=0;ifree_quantity;i+)for(j=0;ji;j+)if(freesj.lengthfreesi.length)max=i;elsemax=j;if(freesmax.lengthjob_length)coutendlSorry,当前没有能满足你申请长度的空闲内存,请稍候再试job_length)freesmax.start+=job_length;freesmax.length-=job_length;elsefor(j=max;jfree_quantity-1;j+)freesj=freesj+1;free_quantity-; cout内存空间成功:)endl;cout内存空间成功:)endl;cout内存空间成功:)endl;void bestMethod()char job_name20; /名字int job_length; /长度int i,j;int max=0,min=0,maxx;coutjob_name;cinjob_length;for(i=0;ifree_quantity;i+)for(j=0;ji;j+)if(freesj.length=freesi.length)max=i;elsemax=j;for(j=0;j=freesi.length)min=i;elsemin=j;if(freesmin.length=job_length)maxx=i;if(freesmaxx.lengthjob_length)coutendlSorry,当前没有能满足你申请长度的空闲内存,请稍候再试job_length)freesmaxx.start+=job_length;freesmaxx.length-=job_length;elsefor(j=maxx;jfree_quantity-1;j+)freesj=freesj+1;free_quantity-; cout内存空间成功:)endl;cout内存空间成功:)endl;cout内存空间成功:)endl;/显示版权信息函数void version()coutendlendl;cout endl;cout 可变分区存储管理模拟系统 endl;cout endl;cout (c)All Right Reserved MQ endl;cout endl;cout version 2008 build 0410endl;cout endl;coutendlendl;/Mainint main()int flag=0;int t=1;int chioce=0;version();initial();flag=readData();while(flag=1) /sort();coutendlendl=endl;cout 可变分区存储管理模拟系统endl;cout=endl;cout 1.最先适用算法申请空间 2.显示空闲表和分配表endl;cout 3.最坏适用算法申请空间 4.最佳适用算法申请空间endl;cout 0.退出endl;coutchioce;switc