主存# includeostream首次自适应算法 hstructprogram { charname[30]；longstartlonglengthstructprogram * next};结构空间{long

开始；longlengthstructspace * next }；void creat()；void allot()；void back()；void回调(program * r)；void排序(space * L)；voidsort(程序);void显示(space * L)；无效显示(程序);space * L；程序；intmain()

="color: rgba(0, 0, 0, 1)">{
    creat();
    int a;
    cout<<"              内存分配与回收模拟"<<endl; 
    cout<<"1:分配内存"<<endl; 
    cout<<"2:回收内存"<<endl; 
    cout<<"0:退出"<<endl;    
    while(1)
    {
        cout<<endl<<"请按键选择：";
        cin>>a;
        if(a>2||a<0)
        {
            cout<<endl<<"输入错误，请重新输入："; 
            continue;
        }
        switch(a)
        {
            case 1: allot();  break;
            case 2: back();  break;
            case 0: goto end; 
        } 
    } 
    end: 
    getchar();
    getchar();
}
void creat()
{
    L=new space;
    space *p=new space;
    p->start=0;
    p->length=128;
    p->next=NULL;
    L->next=p;
    S=new program;
    S->next=NULL;
} 
void allot()
{
    program *q;
    q=new program;
    cout<<"请输入进程名和占用空间大小:"<<endl;
    cin>>q->name>>q->length;
    if(q->length<=0)
    {  
        cout<<"进程空间大小错误."<<endl;
        delete q;
        return;
    } 
    space *p,*r; 
    p=L;
    r=p;
    while(p->next!=NULL&&p->next->length<q->length)
    {
       r=p;
       p=p->next;
    }    
    if(p->next==NULL)
    {
        cout<<"占用空间过大，分配失败"<<endl;
        delete q;
        return;
    }
    else
    {
        q->start=p->next->start;
        q->next=S->next;
        S->next=q;
        
        p->next->length-=q->length;
        if(p->next->length!=0)
           p->next->start+=q->length;
        else
        {
           if(p->next->next!=NULL)
               p->next=p->next->next;
           else
           {
               r->next=NULL;
               delete p->next;
           }     
        }      
    }
    display(L);
    display(S);
}             
void back()
{   
    char name[30];
    cout<<"输入要回收的进程名：";
    cin>>name;
    program *p;
    p=S;
    while(p->next!=NULL)
    {
        if(strcmp(p->next->name, name)==0)
        {
           callback(p); 
           return;
        } 
        p=p->next;
    }
    if(p->next==NULL)
        cout<<"此进程不存在,内存回收失败"<<endl;

}   
void callback(program *t)
{
    program *r; 
    r=t->next; 
    space *p,*q; 
    long n;
    n=r->length; 
    if(L->next==NULL)
    {
        space *w=new space;
        w->start=0;
        w->length=n;
        w->next=NULL;
        L->next=w;
        t->next=r->next;
        delete r;
        cout<<"此进程内存回收完毕."<<endl;    
        display(L);
        display(S); 
        return;
    }    
    p=L->next;
    while(p!=NULL&&p->start<r->start)
    {
        q=p;
        p=p->next; 
    }
    if((q->start+q->length==r->start)&&(r->start+n==p->start)) //上下均空
    {
        q->next=p->next;
        q->length=q->length+p->length+n;
        t->next=r->next;
        delete r; 
    }
    else if(r->start+n==p->start)  //下邻空
    {
        p->start-=n;
        p->length+=n;
        t->next=r->next;
        delete r;
    }
    else if(q->start+q->length==r->start)
    {
        q->length+=n;
        t->next=r->next;
        delete r;
    }
    else 
    {
        space *sp=new space;
        sp->start=r->start; 
        sp->length=n;
        sp->next=L->next;
        L->next=sp; 
        t->next=r->next;
        delete r;
    } 
    cout<<"此进程内存回收完毕."<<endl;    
    display(L);
    display(S);            
} 
void display(space *L)
{
    sort(L); 
    space *p=L->next;
    cout<<endl<<"空闲区情况："<<endl; 
    if(p==NULL)
    {   cout<<"无空闲区了."<<endl; return;} 
    while(p!=NULL)
    { 
        cout<<"起始地址:"<<p->start<<"      长度:"<<p->length<<endl; 
        p=p->next;
    }
}      
void display(program *S)
{
    sort(S); 
    program *p=S->next;
    cout<<endl<<"进程内存分配情况："<<endl; 
    if(p==NULL)
    {   cout<<"内存中无进程."<<endl; return;} 
    while(p!=NULL)
    {
        cout<<"进程名:"<<p->name<<"    起始地址:"<<p->start<<"      长度:"<<p->length<<endl; 
        p=p->next;
    }
    cout<<endl;
}       
void sort(space *L)    //链表排序
{  
   space *p=L->next, *q, *r;
   if(p!=NULL)
   {
      r=p->next;
      p->next=NULL;
      p=r;
      while(p!=NULL)
      {
        r=p->next;
        q=L;
        while(q->next!=NULL&&q->next->start<p->start)
           q=q->next;
        p->next=q->next;
        q->next=p;
        p=r;
      } 
   }
}      
void sort(program *S)    //链表排序
{  
   program *p=S->next, *q, *r;
   if(p!=NULL)
   {
      r=p->next;
      p->next=NULL;
      p=r;
      while(p!=NULL)
      {
        r=p->next;
        q=S;
        while(q->next!=NULL&&q->next->start<p->start)
           q=q->next;
        p->next=q->next;
        q->next=p;
        p=r;
      } 
   }
}