采用可变式分区管理，使用空闲链表实现主存的分配与回收

采用可变式分区管理，使用空闲链表实现主存的分配与回收

#include
#include
#include
#define NULL 0
#define LEN sizeof(struct PCB)

struct PCB{
	int InitAdd;
	int EndAdd;
	int Length;
	int Release;
	char name[5];
	char state[5];
	struct PCB *next;
}; 

	struct PCB a,b,c,d,e,f,*Head;

//初始化 
PCB* init(PCB *Head){
	struct PCB *p;
	a.InitAdd=0;a.Length=10;a.EndAdd=10;strcpy(a.name,"系统");strcpy(a.state,"空表目"); 
	b.InitAdd=10;b.Length=10;b.EndAdd=20;strcpy(b.name,"作业");strcpy(b.state,"已分配"); 
	c.InitAdd=20;c.Length=25;c.EndAdd=45;strcpy(c.name,"作业");strcpy(c.state,"已分配"); 
	d.InitAdd=45;d.Length=20;d.EndAdd=65;strcpy(d.name,"空闲");strcpy(d.state,"未分配"); 
	e.InitAdd=65;e.Length=45;e.EndAdd=110;strcpy(e.name,"作业");strcpy(e.state,"已分配"); 
	f.InitAdd=110;f.Length=146;f.EndAdd=256;strcpy(f.name,"空闲");strcpy(f.state,"未分配"); 	
	Head=&a;
	a.next=&b;
	b.next=&c;
	c.next=&d;
	d.next=&e;
	e.next=&f;
	f.next=NULL;
	printf("起始地址  长度   终止地址     name      状态 \n");
	p=Head;
	while(p!=NULL){
		printf("%4d%10d%8d%12s%11s\n",p->InitAdd,p->Length,p->EndAdd,p->name,p->state);
		p=p->next;
	}
	return Head;
}

//空闲区分配 
void compare(struct PCB *Head,int l){
	struct PCB *p,*s;
	int k=0; 
	p=Head;
	while(p!=NULL){
		if(p->Length>=l&&strcmp(p->name,"空闲")==0){
			k=1;
			printf("作业分配成功！\n"); 
			if(p->Length==l){
			    strcpy(p->name,"作业");
			    strcpy(p->state,"已分配");	
				break;			
			}
			else{
				s=(struct PCB *)malloc(LEN);
			    s->next=p->next;
			    p->next=s;
			    s->EndAdd=p->EndAdd;
			    strcpy(s->name,"空闲");
			    strcpy(s->state,"未分配");			
			    s->InitAdd=p->InitAdd+l;
		     	s->Length=p->Length-l;
			    p->Length=l;
			    p->EndAdd=p->InitAdd+l;
			    strcpy(p->name,"作业");
			    strcpy(p->state,"已分配");
			    break; 
			}
		}
		p=p->next;
	}
	if(k==0)
	    printf("作业等待！\n");
	    printf("起始地址  长度   终止地址     name      状态 \n");
	    p=Head;
	    while(p!=NULL){
		    printf("%4d%10d%8d%12s%11s\n",p->InitAdd,p->Length,p->EndAdd,p->name,p->state);
		    p=p->next;
	    }  
}

//作业输入 
void input(struct PCB *Head){
	int N,l;
	printf("请输入申请作业个数：\n");
	scanf("%d",&N);
	for(int i=0;inext!=NULL){
		if(strcmp(p->name,"空闲")==0&&strcmp(p->next->name,"空闲")==0){
			p->Length=p->Length+p->next->Length;
			p->EndAdd=p->InitAdd+p->Length;
			p->next=p->next->next;
			continue;
		}
		p=p->next;
	}
	printf("起始地址  长度   终止地址     name      状态 \n");
	p=Head;
	while(p!=NULL){
		printf("%4d%10d%8d%12s%11s\n",p->InitAdd,p->Length,p->EndAdd,p->name,p->state);
		p=p->next;
	} 
}

//作业释放顺序 
void release(PCB *Head){
	PCB *p;
	int sum=0,temp=1;
	p=Head;
	while(p!=NULL){
		if(strcmp(p->name,"作业")==0)
		sum++;
		p=p->next;
	}
	printf("作业个数为：%d\n",sum);
	printf("输入作业释放顺序：\n");
	p=Head;
	while(p!=NULL){
		if(strcmp(p->name,"作业")==0)
		scanf("%d",&p->Release);
		p=p->next;
	}
	while(temp<=sum){
		p=Head;
	    while(p!=NULL){
	     	if(p->Release==temp){
		    	strcpy(p->name,"空闲");
		    	strcpy(p->state,"未分配");
		    	mix(Head,temp); 
		    	break;
	    	}
		p=p->next;
	    }
	temp++;
	}
}


//主函数 
int main(){
	PCB *p;
	Head=init(Head);
	input(Head);
	release(Head);
}

若查找可变式分区管理的首次适应算法，请看我的博客。
https://mp.csdn.net/mdeditor/86530244#

谢谢大家观看。