各位帮忙看一下，有什么建议提提。让我头疼好久了。第四个不会写，哪位帮我补充一下。。。

#include <fstream>
#include <string>
using namespace std;
void input(void)
void clear(void)
void main()
{ struct phone
    {string mane;
     int num;
    }man[50];
 phone *p[50];
 
 int i,j,k,s,t;
for (i=0;i<=49;i++)
    p[i]=&man[i];
 while(true)
 {cout<<"请输入要进行的操作"<<endl;
 cout<<"1.输入电话记录"<<endl;
 cout<<"2.删除电话记录"<<endl;
 cout<<"3.查询电话记录"<<endl;
 cout<<"4.保存电话记录"<<endl;
 cout<<"5.读取电话记录"<<endl;
 cout<<"6.退出"<<endl;
 }
 cin >>i;
 switch(i)
 {case(1):{for(j=0;j<=49;j++)
             {if (p[j]->name=NULL& p[j]->nun=NULL)input(j);
            }
                break;
            }
 case(2):cout<<"请输入你要删除的编号：">>endl;
         cin>>k;
         if(p[k]->name=NULL& p[k]->nun=NULL)
             for(s=k;s<=50;s++)
                 p[k]=p[k+1];
 case(3):{ofstream outfile("file1.dat",ios::app|ios::binary);
         outfile.close()
         }
 case(4):
 case(5):{struct phone people[50]
            ifstream infile("file1.dat",ios::init|ios::binary);
            for(t=0;t<50;t++)
                infile.read(char*)&(people[t],sizeof(people[t]));
            infile.close();
            for(t=0;t<50;t++)
                cout<<people[t];
         }
 case(6):abort();
 }
}
void input(j)
{cin>>p[j]->name;
 cin>>p[j]->num;
 break;
}