مشکل در delete , edit

سلام
ممکنه کمکم کنید؟
من یه برنامه با فایل و struct نوشتم که منوی اون 6 تا گزینه داره
ولی متاسفانه 2 و3 که delete و edit هست درست کار نمیکنه
مشکل اینجاست که برای delete مینویسه حذف شد ولی وقتیshow all میکنم دوباره نمایش میده و حذف نشده
برای edit هم اطلاعات قبلی رو حذف میکنه ولی اطلاعات جدید رو جایگزین نمیکنه و در show all اونو نمایش نمیده
بعبارتی فقط حذف میکنه و جایگزین نمیکنه
اگه ممکنه کمک کنید
ممنون

#include <fstream>

#include <conio.h>

#include <iostream>

using namespace std;

void add();

void edit();

void sort();

void show();

void delet();

void search();

struct student

{

    char fname[20];

    char lname[35];

    long int number;

    float ave;

    int f;

};



int main()

{

    int y;

    while(1)

    {

        system("cls");

        system("color 0a");

        cout<<"1-add student"<<endl;

        cout<<"2-edit student"<<endl;

        cout<<"3-delete student"<<endl;

        cout<<"4-search"<<endl;

        cout<<"5-sort"<<endl;

        cout<<"6-show all"<<endl;

        cout<<"7-exit"<<endl;

        cout<<endl<<endl<<endl;

        cout<<"enter your selection(1-7)";

        cin>>y;

        switch(y)

        {

        case 1:

            add();

            break;

        case 2:

            edit();

            break;

        case 3:

            delet();

            break;

        case 4:

            search();

            break;

        case 5:

            sort();

            break;

        case 6:

            show();

            break;

        case 7:

            exit(0);

        default:

            system("cls");

            cout<<"Enter a valid number.";

            _getch();

        }

    }

    return 0;

}

//-------------------------------------------------------------------------------------

void add()

{

    system("cls");

    int n;

    student z;

    ofstream file("a.dat",ios::binary|ios::app);

    if(!file)

    {

        cout<<"can not open the file \n";

        getch();

        return;

    }

    cout<<"enter number of students : ";

    cin>>n;

    for(int i=0;i<n;i++)

    {

        cout<<"enter fname and lname and number and ave : \n";

        cin>>z.fname>>z.lname>>z.number>>z.ave;

        z.f=1;

        file.write((char *)&z,sizeof(student));

    }

    file.close();

    getch();

}

//...............................'''''''''''''''''''  ''''''''''''''''''''''''

void edit()

{

    system("cls");

    student z,r,*pst;

    int c,i;

    long int number1;

    cout<<"enter number1 :\n";

    cin>>number1;

    ifstream file("a.dat",ios::in|ios::binary);

if(!file)

    {

        cout<<"can not open the file \n";

        getch();

    exit(0);

    }



file.read((char *)&z,sizeof(student));

    for(c=0;!file.eof();C++‎)

    {

        file.read((char *)&z,sizeof(student));

    }

    file.close();

pst=new student[c];

ifstream infile("a.dat",ios::in|ios::binary);

if(!infile)

    {

        cout<<"can not open file";

        getch();

        exit(0);

    }

infile.read((char*)pst,c*sizeof(student));

    infile.close();

ofstream outfile("b.dat",ios::out|ios::binary);

    if(!outfile)

    {

        cout<<"can not open file";

        getch();

        return;

    }

    for(i=0;i<c;i++){

if(pst[i].number==number1&& pst[i].f==1)

        {

            cout<<pst[i].fname<<"\n"<<pst[i].lname<<"\n"<<pst[i].number<<"\n"<<pst[i].ave<<"\n\n";

            cout<<"enter new fname and lname and number and ave :\n";

            cin>>r.fname>>r.lname>>r.number>>r.ave;

            outfile.write((char *)&r,sizeof(student));

            

}

else{

r=pst[i];

outfile.write((char *)&r,sizeof(student));

}}

outfile.close();

remove("a.dat");

rename("b.dat","a.dat");

getch();

}

//------------------------------------------------------------------------

void delet()

{

    long int  number1;

    system("cls");

    fstream infile("a.dat",ios::in|ios::out|ios::binary);

    if(! infile)

    {

        cout<<"can not open the file";

        getch();

        exit(0);

    }

    student z;

    cout<<"please  Enter ID for delete";

    cin>>number1;

    infile.read((char*)&z,sizeof(student));

    while(!infile.eof())

    {

        if(z.number=number1){

        z.f=0;

        infile.seekp(-sizeof(student),ios::cur);

        infile.write((char *)&z,sizeof(student));

        cout<<"\t\t\t\n\deleted";

        break;

        }

        infile.read((char *)&z,sizeof(student));}

getch();

}//en of deleted

//**************************************************  ****************************

//**************************************************  ****************************

void search()

{

    system("cls");

    ifstream file("a.dat",ios::in|ios::binary);

    if(!file)

    {

        cout<<"can not open the file \n";

        getch();

        return;

    }

    student z;

    long int number1;

    cout<<"enter number1 :\n";

    cin>>number1;

    file.read((char *)&z,sizeof(student));

    while(!file.eof())

    {    

        if(z.number==number1 && z.f==1)

            cout<<z.fname<<"\n"<<z.lname<<"\n"<<z.number<<"\n"  <<z.ave<<"\n\n";

        file.read((char *)&z,sizeof(student));

    }

    file.close();

    getch();

}

void sort()

{

    system("cls");

    int c;

    student st,*pst;

    ifstream file("a.dat",ios::in|ios::binary);

    if(!file)

    {

        cout<<"can not open file";

        getch();

        return;

    }

    file.read((char*)&st,sizeof(student));

    for(c=0;!file.eof();C++‎)

    {

        file.read((char*)&st,sizeof(student));

    }

    file.close();

    pst = new student[c];

    ifstream infile("a.dat",ios::in|ios::binary);

    if(!infile)

    {

        cout<<"can not open file";

        getch();

        return;

    }

    infile.read((char*)pst,c*sizeof(student));

    infile.close();

    for(int j=c-1;j>0;j--)

    {

        for(int i=0;i<j;i++)

        {

            if(pst[i].ave<pst[i+1].ave)

            {

                st = pst[i];

                pst[i] = pst[i+1];

                pst[i+1] = st;

            }

        }

    }

    ofstream outfile("b.dat",ios::out|ios::binary);

    if(!outfile)

    {

        cout<<"can not open file";

        getch();

        return;

    }

    outfile.write((char*)pst,c*sizeof(student));

    outfile.close();

    remove("a.dat");

    rename("b.dat","a.dat");

    getch();

}

void show()

{

    system("cls");

    student z;

    ifstream file("a.dat",ios::binary|ios::in);

    if(!file)

    {

        cout<<"can not open the file \n";

        getch();

        return;

    }

    file.read((char *)&z,sizeof(student));

    while(!file.eof())

    {

        if(z.f==1)

        {

        cout<<z.fname<<"\n"<<z.lname<<"\n"<<z.number<<"\n"  <<z.ave<<"\n\n";

        }

        file.read((char *)&z,sizeof(student));    

    }

    file.close();

    getch();

}

البته جای delete بالا میخوام از این کد استفاده کنم
ولی اینم مشکل داره
ممکنه برای رفع مشکل edit کد بالا و delete این کد کمکم کنید؟؟؟

#include<fstream>

#include<iostream>

#include<conio.h>

using namespace std;

void add();

void show();

void search();

void delet();

struct student{

    char fname[20];

    char lname[20];

    long int stn;

    float ave;

};

int main()

{

    system("cls");

    int y;

    while(1)

    {

        system("cls") ;

        system("color 3b");

        cout<<"1-add student "<<endl;

        cout<<"2-show student "<<endl;

        cout<<"3-search student "<<endl;

        cout<<"4-delete student "<<endl;

        cout<<"5-exit"<<endl;

            cout<<"\n\n";

        cout<<"enter your number of selection:";

        cin>>y;

        switch(y)

        {

        case 1:

            add();

            break;

        case 2:

            show();

            break;

        case 3:

            search();

            break;

        case 4:

            delet();

            break;

        case 5:

            exit(0);

        default:

            system("cls");

            cout<<"enter a value number:";

             _getch();

        }

    }

    return 0;

}

//------------------------------------------------

void add()

{

    system("cls");

    int n;

    student st;

    ofstream file("a.dat",ios::binary|ios::app);

    if(!file)

    {

        cout<<"can not open the file.\n";

        getch();

        return;

    }

    cout<<"enter number of student:";

    cin>>n;

    for(int i=0;i<n;i++){

        cout<<"enter fname  lname  average  st number:";

        cin>>st.fname>>st.lname>>st.ave>>st.stn;



        file.write((char*)&st,sizeof(student));

    }

    file.close();

    getch();

}

//------------------------------------------------------

void show()

    {

        system("cls");

        student st;

        ifstream file("a.dat",ios::binary|ios::in);

        if(!file)

        {

            cout<<"can not open the file.\n";

            getch();

            return;

        }



        file.read((char*)&st,sizeof(student));

        while(!file.eof())

        {

            cout<<st.fname<<"\t"<<st.lname<<"\t"<<st.ave<<"\t"  <<st.stn<<endl;

        file.read((char*)&st,sizeof(student));

        }

        file.close();

        getch();

}

//-------------------------------------------------------------

void search()

{

    system("cls");

    student st;

    long int number;

    fstream file("a.dat",ios::in|ios::binary|ios::out);

    if(!file)

    {

        cout<<"can not  open the file.\n";

        getch();

        return;

    }

    cout<<"please enter student number for search:";

    cin>>number;

    file.read((char*)&st,sizeof(student));

    while(!file.eof())

    {

        if(st.stn==number)

        {

            cout<<st.fname<<"\t"<<st.lname<<"\t"<<st.ave<<"\t"  <<st.stn<<"\n";

        

        file.read((char*)&st,sizeof(student));

    break;

    }

    else

    {

        cout<<"sorry not found.";

        break;

        }

    }

    getch();

    file.close();

}

//-----------------------------------------------------------

void delet()

{

    system("cls");

long int number1;

int flag=1;

student st;

ifstream in("a.dat",ios::binary|ios::in);

ofstream out("a.dat",ios::binary|ios::out);

if(!in && out)

{

    cout<<"can not open the file.\n";

    getch();

    return;

}

while(flag)

{

    cout<<"enter number for search:";

    cin>>number1;

    in.read((char*)&st,sizeof(student));

    if(st.stn==number1)

    {

        cout<<st.fname<<"\t"<<st.lname<<"\t"<<st.ave<<"\t"  <<st.stn<<"\n";

        cout<<"enter new information:";

        cin>>st.fname>>st.lname>>st.ave>>st.stn;

        out.write("a.dat",ios::binary|ios::out);

        flag=0;

        break;

    }

    else

    {

        cout<<"sorry not found.";

        break;

    }

}

        in.close();

        out.close();

        remove("a.dat");

        rename("temp.dat","a.dat");

        getch();

        ifstream temp("a.dat",ios::in|ios::binary);

        cout<<"fname"<<"\t"<<"lname"<<"\t"<<"ave"<<"\t"<<"  stn"<<"\n";

        temp.read((char*)&st,sizeof(student));

        while(!temp.eof())

        {

            cout<<st.fname<<"\t"<<st.lname<<"\t"<<st.ave<<"\t"  <<st.stn<<"\n";

            temp.read((char*)&st,sizeof(student));

        temp.close();

}

getch();

}

سلام.
من فرصت ندارم کد رو کامل بخونم (بخصوص که بسیار هم ناخوانا است) اما با یه نگاه سریع متوجه شدم در خط 168 از کد اول، جای == نوشته اید = ... شاید operator مربوطه رو درست کنید، عمل حذف با موفقیت انجام بشه. در هر حال، اگر خواستید دقیق نگاه کنم، کدتون رو Refactor کنید و در همین تاپیک مجددا ارسال کنید.

موفق باشید.