os.txt

操作系统链表的实现 操作系统链表的实现

#include<stdio.h> 
#include<string.h> 
#include<iostream.h> 

const int MAXGROUP=10;//定义组的大小 
const int MAXJOB=100;//定义一个作业最大能申请的块数 

//结构体定义 
typedef struct node{ 
int quantity; 
int cell[MAXGROUP]; 
struct node *next; 
}group; 

typedef struct node1{ 
char name[20]; 
int quantity; 
int cell[MAXJOB]; 
struct node1 *next; 
}job; 

group *head; 
int total; 

job *jhead; 

//初始化组函数 
group *initial() 
{ 
int i; 
group *p; 

p=new group; 

p->quantity=0; 
p->next=NULL; 

for(i=0;i<MAXGROUP;i++){ 
p->cell[i]=-1; 
} 

return p; 
} 

//初始化作业函数 
job *initial_job() 
{ 
int i; 
job *p; 

p=new job; 

strcpy(p->name,""); 
p->quantity=0; 
p->next=NULL; 

for(i=0;i<MAXGROUP;i++){ 
p->cell[i]=-1; 
} 

return p; 
} 

//读入空闲块流文件 
void readData() 
{ 
FILE *fp; 
char fname[20]; 
int temp; 
group *p; 

cout<<"请输入初始空闲块数据文件名:"; 

cin>>fname; 

if((fp=fopen("5unix.txt","r"))==NULL){ 
cout<<"错误,文件打不开,请检查文件名:)"<<endl; 
} 
else{ 
cout<<"=================================================="<<endl; 
cout<<"读入的初始空闲块号:"; 
while(!feof(fp)){ 
fscanf(fp,"%d ",&temp); 
if(head->quantity<MAXGROUP){ 
head->cell[head->quantity]=temp; 
head->quantity++; 
} 
else{ 
p=initial(); 
p->next=head; 
head=p; 
p->cell[p->quantity]=temp; 
p->quantity++; 
} 
total++; 
//输出初始数据 
cout<<temp<<" "; 
} 

cout<<endl<<"总空闲块数:"<<total<<endl; 
} 
} 

//查看专用块函数 
void view() 
{ 
int i; 

cout<<endl<<"专用块数据如下:"<<endl; 
cout<<"-------------------------------"<<endl; 
cout<<"所存储的空闲块号:"; 
for(i=0;i<head->quantity;i++){ 
cout<<head->cell[i]<<" "; 
} 
cout<<endl<<"专用块空闲块数为:"<<head->quantity; 
cout<<endl<<"总空闲块数:"<<total<<endl; 
} 


//新申请函数 
void bid() 
{ 
char jobname[20]; 
int number; 
int i; 
job *p; 

cout<<"----------------------------------"<<endl; 
cout<<"请输入新专业名:"; 
cin>>jobname; 
cout<<"所需内存块数:"; 
cin>>number; 

if(number>total){ 
cout<<"所需内存块数大于当前空闲块数,请稍候再试:)"<<endl; 
} 
else{ 
p=initial_job(); 
strcpy(p->name,jobname); 
p->next=jhead->next; 
jhead->next=p; 
p->quantity=number; 
cout<<"所申请到的空闲块号流:"; 
for(i=0;i<number;i++){ 
if(head->quantity>1){ 
cout<<head->cell[head->quantity-1]<<" "; 
head->quantity--; 
p->cell[i]=head->cell[head->quantity-1]; 
} 
else{ 
cout<<head->cell[0]<<" "; 
p->cell[i]=head->cell[head->quantity-1]; 
head->quantity--; 
if(head->next!=NULL){ 
head=head->next; 
} 
} 
total--; 
} 
} 
cout<<endl; 
} 

//撤消作业 
void finish() 
{ 
char jobname[20]; 
int i; 
job *p,*q; 
group *r; 

cout<<"请输入要撤消的作业名:"; 
cin>>jobname; 

q=jhead; 
p=jhead->next; 
while((p!=NULL)&&(strcmp(p->name,jobname))){ 
q=q->next; 
p=p->next; 
} 

if(p==NULL){ 
cout<<"Sorry,没有该作业"<<endl; 
} 
else{ 
for(i=0;i<p->quantity;i++){ 
if(head->quantity<MAXGROUP){ 
head->cell[head->quantity]=p->cell[i]; 
head->quantity++; 
} 
else{ 
r=initial(); 
r->next=head; 
head=r; 
r->cell[r->quantity]=p->cell[i]; 
r->quantity++; 
} 
} 
total+=p->quantity; 

q->next=p->next; 
delete p; 
} 
} 

//显示版权信息函数 
void version() 
{ 
cout<<" 　　　 　模拟UNIX的成组链接法 　 　　　　 "<<endl; 
cout<<" "<<endl; 

cout<<""<<endl; 

cout<<endl<<endl; 
} 


void main() 
{ 
int f=1; 
int chioce; 

version(); 
head=initial(); 
total=0; 
jhead=initial_job(); 

readData(); 

while(f==1){ 
cout<<"===================================================="<<endl; 
cout<<" 模拟UNIX的成组链接法 "<<endl; 
cout<<"===================================================="<<endl; 
cout<<"1.申请空闲块 2.撤消作业 3.查看专用块 0.退出"<<endl; 
cout<<"请选择:"; 
cin>>chioce; 

switch(chioce){ 
case 1: 
bid(); 
break; 
case 2: 
finish(); 
break; 
case 3: 
view(); 
break; 
case 0: 
f=0; 
break; 
default: 
cout<<"选择错误!"<<endl; 
} 
} 

}