#include<stdio.h>
#include<stdlib.h>
#include<time.h>
struct memory{int memory_number;char proname;
};
struct memory memory_table[20]={0};
struct page{ char proname;//进程名称int prosize;//进程大小  int pagetable[10];//进程页表
};//页表
struct page page_table[10]={0};int allocate(int memorysize,int i,int pagesize);//为进程分配内存空间
int reclaim(int memorysize,char proname);//释放进程占用的空间void output();
int main()
{int pagesize;//分页大小int memorysize=80;//内存大小char proname;int choice;//操作选择int i;printf("Please enter the page size：\n");scanf("%d",&pagesize);//初始化for(i=0;i<20;i++){memory_table[i].memory_number=i;memory_table[i].proname='0';}for(i=0;i<10;i++){page_table[i].proname='0';}srand((unsigned)time(NULL));for(i=0;i<7;i++){int number=rand()%19+1;memory_table[number].proname='a';memorysize--;}output();//进入存储分配while(memorysize!=0){printf("Selecting Operation\n1.Allocate  2.Reclaim\n");scanf("%d",&choice);if(choice==1){for( i=0;i<10;i++){if(page_table[i].proname=='0'){getchar();printf("Please enter process name：");scanf("%c",&page_table[i].proname);getchar();printf("Please enter process size：");scanf("%d",&page_table[i].prosize);break;}}memorysize=allocate(memorysize,i,pagesize);}else{printf("Please enter process name：");getchar();scanf("%c",&proname);memorysize=reclaim(memorysize,proname);}output();}return 0;
}int  allocate(int memorysize,int i,int pagesize)
{int k;int j;for(k=0;k<(page_table[i].prosize/pagesize);k++){for( j=0;j<20;j++){if(memory_table[j].proname=='0'){memory_table[j].proname=page_table[i].proname;page_table[i].pagetable[k]=j;memorysize--;break;}}}return memorysize;
}int reclaim(int memorysize,char proname)
{int j;int k;for( j=0;j<20;j++){if(memory_table[j].proname==proname){memory_table[j].proname='0';memorysize++;}}for (j=0;j<10;j++){if(page_table[j].proname==proname){page_table[j].proname='0';page_table[j].prosize=0;for(k=0;k<10;k++){page_table[j].pagetable[k]=0;}break;}}return memorysize;
}void output(){int i;printf("————————memory allocation——————————\n");printf("Physical Block No.   Process Name\n");for(i=0;i<20;i++){printf("%d                          %c\n",memory_table[i].memory_number , memory_table[i].proname);}
}