#include<stdio.h>
int MA[4];     /*空闲块数组*/
int A[9][4]={{3,1,2,3},{3,4,5,6},{0,0,0,0},{0,0,0,0},{3,0,7,8},
             {0,0,0,0},{0,0,0,0},{0,0,0,0},{0,0,0,0}};  /*磁盘空间专用块*/
int mark[9];       /*存放已分配的块*/
int No=0;              /*已分配的块数*/
void display1()//无参数无返回值的显示类函数，重要的是函数体
{   int i,j,temp,count;
    No=0;
    if(MA[1]!=0)
       {   i=MA[0];
           printf("\n第1组:");
           for(j=1;j<=i;j++)
              {   printf("%d   ",MA[j]);
                  mark[++No]=MA[j];
              }                 
           temp=MA[1];
           count=2;
           while(A[temp][1]!=0)
              {   printf("\n第%d组:",count);
                  i=A[temp][0];
                  for(j=1;j<=i;j++)
                     {   printf("%d   ",A[temp][j]);
                         mark[++No]=A[temp][j];
                     }   
                  count++;
                  temp=A[temp][1];
              }
           printf("\n第%d组:",count);
           i=A[temp][0];
           for(j=2;j<=i+1;j++)
              if(A[temp][j]>0)
                 {   printf("%d   ",A[temp][j]);
                     mark[++No]=A[temp][j];
                 }   
       }
    else
       {   i=MA[0];
           if(i==1)
              printf("\n空闲块已全部申请");
           else   
              {   printf("\n第1组:");
           for(j=2;j<=i;j++)
                     {   printf("%d   ",MA[j]);
                         mark[++No]=MA[j];
                     }   
              }   
       }
}

void display()  /*显示分组情况*/
{   int i,j;
    if(MA[0]!=0)
       display1();
    else
       {   i=MA[1];
           for(j=0;j<=3;j++)
              MA[j]=A[i][j];
           display1();     
       }   
}
void assign()      /*分配空闲块*/
{   int s,i;
    if(MA[0]>1)       /*若该组不止一个空闲块*/
       {   i=MA[0];
           s=MA[i];
           MA[0]--;
           printf("\n空闲块数为:%d",s);     
       }
    else if(MA[0]==1)      /*只剩一个空闲块*/
       {   if(MA[1]!=0)           /*还有其它空闲块组*/
              {   s=MA[1];
                  for(i=0;i<=3;i++)
                     A[0][i]=A[s][i];
                  MA[0]--;
                  printf("\n空闲块数为:%d",s);   
              }
           else                    /*没有其它空闲块组*/
              {   printf("\n无空闲块");
                  return;
              }   
       }
    else                    /*当前组已分配完*/
       {   for(i=0;i<=3;i++)
              MA[i]=A[0][i];
           assign();   
       }
    display();         /*显示分组情况*/
}

void callback()         /*回收空闲块*/
{   int i,j,temp;
    printf("\n输入您想申请的空闲块号:");
    scanf("%d",&j);
    getchar();             /*得到待回收的空闲块号*/
    for(temp=1;temp<=No;temp++)
       {   if(mark[temp]==j)
              break;
       }
    if(temp<No+1)        /*若该空闲块已在，退出*/
       {   printf("\n该空闲块已存在");
    return;
       }   
    if(MA[0]<3)         /*当前组不满3块*/
       {   i=MA[0];
           MA[i+1]=j;
           MA[0]++;
       }
    else              /*已有3块*/
       {   for(i=0;i<=3;i++)
              A[j][i]=MA[i];
           MA[0]=1;
           MA[1]=j;   
       }   
    display();      /*显示*/
}
void menu()                /*功能选择函数*/
{   int choice;
    char judge;
    printf("\n请输入您的选择:(1--申请,2--回收):");
    scanf("%d",&choice);
    getchar();
    if(choice==1)
       assign();
    else if(choice==2)
       callback();
    else
       printf("\n无效命令!");
    printf("\n继续选择?(y--Yes,n--Not):");
    scanf("%c",&judge);
    getchar();
    if(judge=='y')
       menu();
    else
       {   printf("\nNow the graph is:");
    display();
           printf("\npress any key to quit");
         
       }   
}
main()
{   int i;
    for(i=0;i<=3;i++)
       MA[i]=A[0][i];
    display();
    menu();
}