#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#define MAX_SIZE 32767
typedef struct node {
int id;
int adr;
int size;
struct node *next;
}Node;
Node *head1,*head2,*back1,*back2,*assign;
int request;
int check(int add,int siz,char c)
{
Node *p,*head;
int check=1;
if(add<0||siz<0)
check=0;/*
地址和大小不能为负
*/
if(c=='f'||c=='F')
head=head1;
else
head=head2;
p=head->next;
while((p!=NULL)&&check)
if(((add<p->adr)&&(add+siz>p->adr))||((add>=p->adr)&&(add<p->adr+p->size)))
check=0;
else
p=p->next;
if(check==0)
printf("\t输入释放区地址或大小有错误！！！\n");
return check;
}
void init()
{
Node *p;
head1=(Node*)malloc(sizeof(Node));
head2=(Node*)malloc(sizeof(Node));
p=(Node*)malloc(sizeof(Node));
head1->next=p;
head2->next=p;
p->size=MAX_SIZE;
p->adr=0;
p->next=NULL;
p->id=0;
}
Node* assignment1(int num,int req)
{
Node *before,*after,*ass;
ass=(Node*)malloc(sizeof(Node));
before=head1;
after=head1->next;
ass->id=num;
ass->size=req;
while(after->size<req)
{
before=before->next;
after=after->next;
}
if(after==NULL)
{
ass->adr=-1; }
else
{
if(after->size==req)
{
before->next=after->next;
ass->adr=after->adr;
}
else
{
after->size-=req;
ass->adr=after->adr;
after->adr+=req;
}
}
return ass;
}
void acceptment1(int address,int siz,int rd)
{
Node *before,*after;
int insert=0;
back1=(Node*)malloc(sizeof(Node));
before=head1;
after=head1->next;
back1->adr=address;
back1->size=siz;
back1->id=rd;
back1->next=NULL;
while(!insert&&after)
{//将要被回收的分区插入空闲区（按首址大小从小到大插入）
if((after==NULL)||((back1->adr<=after->adr)&&(back1->adr>=before->adr)))
{
before->next=back1;
back1->next=after;
insert=1;
}
else
{
before=before->next;
after=after->next;
}
}
if(insert)
{
if(back1->adr==before->adr+before->size)
{//和前边分区合并
before->size+=back1->size;
before->next=back1->next;
free(back1);
}
else if(after&&back1->adr+back1->size==after->adr)
{//和后边分区合并
back1->size+=after->size;
back1->next=after->next;
back1->id=after->id;
free(after);
after=back1;
}
printf("\t首先分配算法回收内存成功！\n"); }
else
printf("\t首先分配算法回收内存失败！\n"); }
Node* assignment2(int num,int req)
{
Node *before,*after,*ass,*q;
ass=(Node*)malloc(sizeof(Node));
q=(Node*)malloc(sizeof(Node));
before=head2;
after=head2->next;
ass->id=num;
ass->size=req;
while(after->size<req)
{
before=before->next;
after=after->next;
}
if(after==NULL)
{
ass->adr=-1;
}
else
{
if(after->size==req)
{
before->next=after->next;
ass->adr=after->adr;
}
else
{
q=after;
before->next=after->next;
ass->adr=q->adr;
q->size-=req;
q->adr+=req;
before=head2;
after=head2->next;
if(after==NULL)
{
before->next=q;
q->next=NULL;
}
else
{
while((after->size)<(q->size))
{
before=before->next;
after=after->next;
}
before->next=q;
q->next=after;
}
}
}
return (ass);
}
void acceptment2(int address,int siz,int rd)
{
Node *before,*after;
int insert=0;
back2=(Node*)malloc(sizeof(Node));
before=head2;
after=head2->next;
back2->adr=address;
back2->size=siz;
back2->id=rd;
back2->next=NULL;
if(head2->next==NULL)
{//空闲队列为空
head2->next=back2;
head2->size=back2->size;
}
else
{//空闲队列不为空
while(after)
{
if(back2->adr==after->adr+after->size)
{//和前边空闲分区合并
before->next=after->next;
after->size+=back2->size;
back2=after;
}
else
{
before=before->next;
after=after->next;
}
}
before=head2;
after=head2->next;
while(after)
{
if(after->adr==back2->adr+back2->size)
{//和后边空闲区合并
before->next=after->next;
back2->size+=after->size;
}
else
{
before=before->next;
after=after->next;
}
}
before=head2;
after=head2->next;
while(!insert)
{//将被回收的块插入到恰当的位置（按分区大小从小到大）
if(after==NULL||((after->size>back2->size)&&(before->size<back2->size)))
{
before->next=back2;
back2->next=after;
insert=1;
break;
}
else
{
before=before->next;
after=after->next;
}
}
}
if(insert)
printf("\t最佳适应算法回收内存成功！\n");
else
printf("\t最佳适应算法回收内存失败！！\n"); }
void print(char choice)//输出空闲区队列信息
{
Node *p;
if(choice=='f'||choice=='F')
p=head1->next;
else
p=head2->next;
if(p)
{
printf("\n空闲区队列的情况为：\n");
printf("\t编号\t首址\t终址\t大小\n");
while(p)
{
printf("\t%d\t%d\t%d\t%d\n",p->id,p->adr,p->adr+p->size-1,p->size);
p=p->next;
}
}
}
void menu()//菜单及主要过程
{
char chose;
int ch,num,r,add,rd;
while(1)
{
system("cls");
printf("选择最先适应算法请输入F，选择最佳适应算法请输入B，退出程序请输入E\n\n");
printf("请输入你的选择:");
scanf("%c",&chose);
if(chose=='e'||chose=='E')
exit(0);
else
{
system("cls");
while(1)
{
if(chose=='f'||chose=='F')
printf("最先适应算法（First-Fit)模拟:\n");
if(chose=='b'||chose=='B')
printf("最佳适应算法(Best-Fit)模拟:\n");
printf("1.分配内存,2.回收内存,3.查看内存,4.返回\n\n");
printf("请输入你的选择:");
scanf("%d",&ch);
fflush(stdin);
switch(ch)
{
case 1:
printf("输入申请的分区大小：");scanf("%d",&r);
if(chose=='f'||chose=='F')
assign=assignment1(num,r);
else
assign=assignment2(num,r);
if(assign->adr==-1)
{
printf("分配内存失败！\n"); }
else
printf("分配成功！分配的内存的首址为:%d\n",assign->adr);
break;
case 2:
printf("输入释放的内存的首址：");scanf("%d",&add);
printf("输入释放的内存的大小：");scanf("%d",&r);
printf("输入释放的内存的编号：");scanf("%d",&rd);
if(check(add,r,chose))
{
if(chose=='f'||chose=='F')
acceptment1(add,r,rd);
else
acceptment2(add,r,rd);
}
break;
case 3:
print(chose);
break;
case 4:
menu();
break;
}
}
}
}
}
void main()//主函数
{
init();
menu();
}
