ff.cpp

通过最佳适应算法实现内存的分配与回收~很不错的程序

#include<stdio.h>
struct kongkuai
{int startaddr;
int size;
int flag;
}kongxq[6]={
{10,20,1},
{50,50,1},
{150,100,1},
{300,60,1},
{400,150,1},
{700,200,1}
};

int allocate(int jobsize)
{
   int i;
   int t=0;
   for(i=0;i<6;i++)
    if(kongxq[i].flag==1&&kongxq[i].size>jobsize)
	{
		kongxq[i].startaddr+=jobsize;
		kongxq[i].size-=jobsize;
		t=1;
		return kongxq[i].startaddr-jobsize;
	}
	else
	if(kongxq[i].flag==1&&kongxq[i].size==jobsize)
	{
		kongxq[i].flag=0;
		t=1;
		return kongxq[i].startaddr;
	}
	if(t==0)
		return false;
	return 1;
}

circle()
{
	int i,j;
	struct kongkuai temp;
	for(i=0;i<6;i++)
		for(j=0;j<6;j++)
            if(kongxq[j].size>kongxq[j+1].size)
			{
				temp.startaddr=kongxq[j].startaddr;
				temp.size=kongxq[j].size;
				temp.flag=kongxq[j].flag;
				kongxq[j].startaddr=kongxq[j+1].startaddr;
				kongxq[j].size=kongxq[j+1].size;
				kongxq[j].flag=kongxq[j+1].flag;
				kongxq[j+1].startaddr=temp.startaddr;
				kongxq[j+1].size=temp.size;
				kongxq[j+1].flag=temp.flag;
			}
	for(i=0;i<6;i++)
	    for(j=0;j<6;j++)
            if(kongxq[j].flag==0&&kongxq[j+1].flag==1)
			{
				temp.startaddr=kongxq[j].startaddr;
				temp.size=kongxq[j].size;
				temp.flag=kongxq[j].flag;
				kongxq[j].startaddr=kongxq[j+1].startaddr;
				kongxq[j].size=kongxq[j+1].size;
				kongxq[j].flag=kongxq[j+1].flag;
				kongxq[j+1].startaddr=temp.startaddr;
				kongxq[j+1].size=temp.size;
				kongxq[j+1].flag=temp.flag;
			}
   return 1;
}

callback()
{
	int s,len,t1=0,t2=0,t3=0,i,j;
	printf("请输入回收区的起始地址:\n");
	scanf("%d",&s);
	printf("请输入回收区的大小:\n");
	scanf("%d",&len);
	for(i=0;i<6;i++)
	{
		if((kongxq[i].startaddr==s+len)&&(kongxq[i].flag==1))
		{
			len+=kongxq[i].size;
			t1=1;
			for(j=0;j<6;j++)
			    if((kongxq[j].startaddr+kongxq[j].size==s)&&(kongxq[j].flag==1))
				{
					kongxq[i].flag=0;
					//kongxq[j].startaddr=
					kongxq[j].size=kongxq[j].size+len;

					t2=1;
					break;
				}
			if(t2==0)
			{
				kongxq[i].startaddr=s;
				kongxq[i].size=len;
				break;
			}
		}
	}
	if(t1==0)
	{
		for(i=0;i<6;i++)
		{
			if((kongxq[i].startaddr+kongxq[i].size==s)&&(kongxq[i].flag==1))
			{
				kongxq[i].size+=len;
				t3=1;
				break;
			}
			if(t3==0)
				for(j=0;j<6;j++)
					if(kongxq[j].flag==0)
					{
						kongxq[j].startaddr=s;
						kongxq[j].size=len;
						kongxq[j].flag=1;
						break;
					}
		}
		
	}

return 1;
}

void print()
{
	int i;
	printf("\n         起始地址  |    大小    |    标记      \n\n");
	for(i=0;i<6;i++)
	{
		printf("           %3d     |    %3d     |    %3d         \n",
			kongxq[i].startaddr,kongxq[i].size,kongxq[i].flag);
	}
	printf("\n");
}

void main()
{
	int jobsize,start;
	char end;
    printf("\n是否有作业请求空闲区？y or n:");
	while((end=getchar())=='y')
	{
		printf("初始空闲区状态：\n");
		circle();
		print();
		printf("请输入请求空闲区的作业大小：");
		scanf("%d",&jobsize);
        start=allocate(jobsize);
		circle();
		printf("分配后空闲区状态：\n");
		print();
		if(!start)
			printf("没有适合的空闲区大小！\n");
		else
			printf("作业起始地址：%d\n",start);
            printf("作业大小：%d\n",jobsize);
       callback();
    	circle();
	   print();
		printf("是否有其他的作业请求？ y or n:");
		end=getchar();
	}
	
}