main()
{
int s[21][4];
int i,j,x,y;
char str[4];
for(i=0;i<21;i++)
for(j=0;j<4;j++)
s[i][j]=0;
while(1)
{
printf("Please enter your choose:");
scanf("%s",str);
if(str[0]=='n'||str[0]=='N')
break;
x=(str[0]-'0')*10+(str[1]-'0');
str[2]=toupper(str[2]);
y=str[0]-'A';
if(s[x][y]==1)
continue;
else
{
printf("Please enter your name and ID:");
//在这里录入姓名和身份证号码
break;
}
}
printf("\n");
}