Any suggestion about how to make the program better?

[goshko1]

Any suggestions?
Build a detection model (and file and array storage by adding), and update (deposit and withdraw) time deposits from a certain number of depositors (up to 30).

The data for each depositor should have the following structure: Name, Address, M3 (amount, date), M6 (amount, date), M12 (amount, date) where the date indicates the last draw or deposit the current cash amount quarterly, six-month, and annual deposit.
The program also provides features for:
a) Entering and updating the annual interest rates for each term deposit.
b) Listing and reference for a depositor by name.
c) Recalculating deposits for the current date and displaying a full list of depositors with corresponding deposits, sorting in ascending order.

#include<iostream>
#include<cmath>
#define N 30 
using namespace std;

typedef struct{ 
char data[12];  
double suma;}
mesec;
typedef struct{ 
char ime[25];  
char adres[20]; 
 mesec M3,M6,M12;  
 double smetka;}
 vlojiteli;

 void input();
 void vnasqne();
 void teglene();
 void aktualizaciq();
 void spravka();
 void izvejdane();
 int menu();
 void disp();
 void load();
 void save();
 vlojiteli A[N];
 int top=0;
 
 int main()
 {
 int i;
 cout<<"\n Load from file";
 load();
 	do
{
    i=menu();
    	    switch(i)
    	    	{
    	    	    case 1:input();break;
    	    	    case 2:vnasqne();break;
    	    	    case 3:teglene();break;
    	    	    case 4:aktualizaciq();break;
    	    	    case 5:spravka();break;
    	    	    case 6:izvejdane();break;
    	    	    case 7:save();break;
    	    	}
}
			
			while(i!=8);}
			int menu()
                                    {
        	int ch;
  			cout<<" MENU"<<endl;
   			cout<<" 1.Vyvejdane \n"<<endl;
   			cout<<" 2.Vnasqne po smetka \n"<<endl;
   	   		cout<<" 3.Teglene ot smetka \n"<<endl;
   	     	cout<<" 4.Aktualizaciq na lihvi \n"<<endl;
   	     	cout<<" 5.Spravka za vlojitel po Ime \n "<<endl;
   	     	cout<<" 6.Izvejdane na vsichki vlojiteli sortirani v spisyk \n "<<endl;
   	     	cout<<" 7.Syhrani fail \n "<<endl;
   	     	cout<<" 8.Izhod \n "<<endl;
   	    do
        {
        cout<<"\n Izbor: ";
   cin>>ch;
      }
       while(ch<1||ch>8);
             return(ch);
             }
             
             void disp(int i)
             { 
             
                cout<<"\n Ime:"<<A[i].ime;
                cout<<"\n Adress:"<<A[i].adres;
                cout<<"\n M3 data:"<<A[i].M3.data<<"  M3 suma:"<<A[i].M3.suma<<endl;
                cout<<"\n M6 data:"<<A[i].M6.data<<"  M6 suma:"<<A[i].M6.suma<<endl;
                cout<<"\n M12 data:"<<A[i].M12.data<<"  M12 suma:"<<A[i].M12.suma<<endl;
                cout<<"\n Smetka:"<<A[i].smetka;}void input(){int i,n;do{cout<<"Broi vlojiteli:";
                cin>>n;
                            }
                            while (n<1||n>N);
                               fflush(stdin);
                               	for(i=top;i<top+n;i++)	{cout<<"nIme:";cin>>A[i].ime;
                               	cout<<"\n Adress:";cin>>A[i].adres;
                               	cout<<"\n M3 data:"; cin>>A[i].M3.data;
                               	cout<<"\n M3 suma:";
                               	cin>>A[i].M3.suma;
                               	A[i].smetka+=A[i].M3.suma;
                               	cout<<"\n M6 data:";
                               	cin>>A[i].M6.data;
                               	cout<<"\n M6 suma:";
                               	cin>>A[i].M6.suma;
                               	A[i].smetka+=A[i].M6.suma;
                               	cout<<"\n M12 data:";
                               	cin>>A[i].M12.data;
                               	cout<<"\n M12 suma:";
                               	cin>>A[i].M12.suma; A[i].smetka+=A[i].M12.suma;
                               			  	  	}
                               			  	  	top+=n;}void vnasqne(){int n,p,i;
                               			  	  	do{cout<<"\n Izberete nomer na vlojitel:";
                               			  	  	cin>>n;} while(n<1||n>N);
        										cout<<"\n Izberete vnoska za trimesechie,polovin godina ili edna godina:";
          										cin>>p;
												  	if(p==3)
													        for(i=n;i<n;i++)
           											{
													   cout<<"vyvedete data na vnasqne:";
           												cin>>A[i].M3.data;
           												cout<<"vyvedete suma na vnasqne:";
           												cin>>A[i].M3.suma;A[i].smetka+=A[i].M3.suma;
            										}
            					if(p==6)   
				   					for(i=n;i<n;i++)
                    {
                        cout<<"vyvedete data na vnasqne:";
cin>>A[i].M6.data;
cout<<"vyvedete suma na vnasqne:";
cin>>A[i].M6.suma;A[i].smetka+=A[i].M6.suma;
					}
	if(p==12)      for(i=n;i<n;i++)
        {
            cout<<"vyvedete data na vnasqne:";
cin>>A[i].M12.data;
cout<<"vyvedete suma na vnasqne:";
cin>>A[i].M12.suma;A[i].smetka+=A[i].M12.suma;
    	}
    	}
    	void teglene(){ int i,n;  double s;
    	do
            {cout<<"\n Izberete nomer na vlojitel:";
    	 cin>>n;
    	 }
    	 while(n<1||n>N);
cout<<"\n Izberete sumata,koqto iskate da izteglite:";
	cin>>s;
		for(i=n;i<n;i++)
                {
                    if(s<A[i].smetka)	A[i].smetka=A[i].smetka-s;

else cout<<"Nqmate tolkowa pari!";
}
}
void aktualizaciq()
{
    int n,i;
    double p;
    do
        {
            cout<<"\n Vyvedete srochen vlog,za koito iskate da promenite lihvata:";
cin>>n;
}
 while(n!=3 || n!= 6 || n!=12);
  cout<<"\n Vyvedete lihva v realno chislo:";
   cin>>p;
    for(i=0;i<N;i++)
        {
            	  if(n==3) A[i].M3.suma = A[i].M3.suma * p + A[i].M3.suma;
if(n==6) A[i].M6.suma = A[i].M6.suma * p + A[i].M6.suma;
if(n==12) A[i].M12.suma = A[i].M12.suma * p + A[i].M12.suma;
}
}
void spravka()
{
    int i; char n[15];
    cout<<"\n Vyvedi ime:";
    cin>>n;  for(i=0;i<N;i++)
    {
        if(A[i].ime==n) disp(i);
        }
        }
        void izvejdane()
        {
            int i,k,z; double temp;
            for(i=0;i<N;i++)
                for(z=i+1;z<N+1;z++)
                if(A[i].smetka>A[z].smetka)
                {
                    temp=A[i].smetka;
A[i].smetka=A[z].smetka;
A[z].smetka=temp;
}
for(i=0;i<N;i++)	disp(i);
}
void load()
{
        FILE *fp;    int i;
        if((fp=fopen("vlojiteli12.dat", "rb"))==NULL)
            {
            cout<<"\n EROR 404: File not found! ";
			return;
			}
if(fread(&top, sizeof(top), 1, fp)!=1)
    {
        cout<<"\n Error size"; exit(1);
	}
        	for(i=0;i<top;i++)
            if(fread(&A[i], sizeof(vlojiteli),1,fp)!=1)
            {
            cout<<"\n Error reading structure!"; exit(1);
			}
			}


void save()
{
    FILE *fp;
    int i;
    if((fp=fopen("vlojiteli12.dat", "wb"))==NULL)
        {
        cout<<"\n Error saving file!";
		return;
		}
if(fwrite(&top, sizeof(top), 1, fp)!=1)
    {
    cout<<"\n Error w top";
	exit(1);
	}
	for(i=0;i<top;i++)
    if(fwrite(&A[i], sizeof(vlojiteli),1,fp)!=1)
    {
        cout<<"\n Error writing str!";
exit(1);
}
fclose(fp);
}

[TheIdeasMan]

12:17: error: expected initializer before 'A'

Line 12 is not a declaration of a function, nor is it a declaration of an array named A.

Note that global variables are bad news in general, and line 3 is too.

Instead of a #define use a const variable instead:

const int N = 30;

or better a constexpr:
constexpr int N = 30;

Today I have been watching videos from cppcon 2018. One of the things said was that C is part of C++ for backwards compatibility. In other words, one can #include C code from an old project and still compile it, but write the new code in C++.

With that in mind, the first thing to do would be to use a std::vector instead of an array, it's a shame a lot of teachers won't let their students do this.

[goshko1]

So i have managed to get most of the things to work ,but from case 2 to case 5 i can't seem to make the program do something and i don't know why.Hope you have something that may help me.

[salem c]

Pick an indentation style (one that isn't chaotic) and stick to it.
https://en.wikipedia.org/wiki/Indentation_style

[goshko1]

Okay here it is.Can you help me now? And hope you understand it.

#include<iostream>
#include<cmath>
#define N 30 
using namespace std;

 
typedef struct
{
  
char data[12];
   
double suma;
} 
mesec;

typedef struct
{
  
char ime[25];
   
char adres[20];
   
mesec M3, M6, M12;
   
double smetka;
} 
vlojiteli;

 
void input ();

void vnasqne ();

void teglene ();

void aktualizaciq ();

void spravka ();

void izvejdane ();

int menu ();

void disp ();

void load ();

void save ();

vlojiteli A[N];

int top = 0;

 
int
main () 
{
  
int i;
  
cout << "\n Load from file";
  
load ();
  
  do
    
    {
      
i = menu ();
      
switch (i)
	
	{
	
case 1:
	  input ();
	  break;
	
case 2:
	  vnasqne ();
	  break;
	
case 3:
	  teglene ();
	  break;
	
case 4:
	  aktualizaciq ();
	  break;
	
case 5:
	  spravka ();
	  break;
	
case 6:
	  izvejdane ();
	  break;
	
case 7:
	  save ();
	  break;
	
}
    
}
  
 
while (i != 8);
}


int
menu () 
{
  
int ch;
  
cout << " MENU" << endl;
  
cout << " 1.Vyvejdane \n" << endl;
  
cout << " 2.Vnasqne po smetka \n" << endl;
  
cout << " 3.Teglene ot smetka \n" << endl;
  
cout << " 4.Aktualizaciq na lihvi \n" << endl;
  
cout << " 5.Spravka za vlojitel po Ime \n " << endl;
  
cout << " 6.Izvejdane na vsichki vlojiteli sortirani v spisyk \n " << endl;
  
cout << " 7.Syhrani fail \n " << endl;
  
cout << " 8.Izhod \n " << endl;
  
  do
    
    {
      
cout << "\n Izbor: ";
      
cin >> ch;
    
}
  
while (ch < 1 || ch > 8);
  
return (ch);

}


 
void
disp (int i) 
{
  
 
cout << "\n Ime:" << A[i].ime;
  
cout << "\n Adress:" << A[i].adres;
  
cout << "\n M3 data:" << A[i].M3.data << "  M3 suma:" << A[i].M3.
    suma << endl;
  
cout << "\n M6 data:" << A[i].M6.data << "  M6 suma:" << A[i].M6.
    suma << endl;
  
cout << "\n M12 data:" << A[i].M12.data << "  M12 suma:" << A[i].M12.
    suma << endl;
  
cout << "\n Smetka:" << A[i].smetka;
} void

input ()
{
  int i, n;
  do
    {
      cout << "Broi vlojiteli:";
      
cin >> n;
    
}
  
while (n < 1 || n > N);
  
fflush (stdin);
  
for (i = top; i < top + n; i++)
    {
      cout << "nIme:";
      cin >> A[i].ime;
      
cout << "\n Adress:";
      cin >> A[i].adres;
      
cout << "\n M3 data:";
      cin >> A[i].M3.data;
      
cout << "\n M3 suma:";
      
cin >> A[i].M3.suma;
      
A[i].smetka += A[i].M3.suma;
      
cout << "\n M6 data:";
      
cin >> A[i].M6.data;
      
cout << "\n M6 suma:";
      
cin >> A[i].M6.suma;
      
A[i].smetka += A[i].M6.suma;
      
cout << "\n M12 data:";
      
cin >> A[i].M12.data;
      
cout << "\n M12 suma:";
      
cin >> A[i].M12.suma;
      A[i].smetka += A[i].M12.suma;
    
}
  
top += n;
}

void
vnasqne ()
{
  int n, p, i;
  
  do
    {
      cout << "\n Izberete nomer na vlojitel:";
      
cin >> n;
    }
  while (n < 1 || n > N);
  
cout <<
    "\n Izberete vnoska za trimesechie,polovin godina ili edna godina:";
  
cin >> p;
  
if (p == 3)
    
for (i = n; i < n; i++)
      
      {
	
cout << "vyvedete data na vnasqne:";
	
cin >> A[i].M3.data;
	
cout << "vyvedete suma na vnasqne:";
	
cin >> A[i].M3.suma;
	A[i].smetka += A[i].M3.suma;
      
}
  
if (p == 6)
    
for (i = n; i < n; i++)
      
      {
	
cout << "vyvedete data na vnasqne:";
	
cin >> A[i].M6.data;
	
cout << "vyvedete suma na vnasqne:";
	
cin >> A[i].M6.suma;
	A[i].smetka += A[i].M6.suma;
      
}
  
if (p == 12)
    for (i = n; i < n; i++)
      
      {
	
cout << "vyvedete data na vnasqne:";
	
cin >> A[i].M12.data;
	
cout << "vyvedete suma na vnasqne:";
	
cin >> A[i].M12.suma;
	A[i].smetka += A[i].M12.suma;
      
}

}


void
teglene ()
{
  int i, n;
  double s;
  
  do
    
    {
      cout << "\n Izberete nomer na vlojitel:";
      
cin >> n;
    
}
  
while (n < 1 || n > N);
  
cout << "\n Izberete sumata,koqto iskate da izteglite:";
  
cin >> s;
  
for (i = n; i < n; i++)
    
    {
      
if (s < A[i].smetka)
	A[i].smetka = A[i].smetka - s;
      
 
      else
	cout << "Nqmate tolkowa pari!";
    
}

}


void
aktualizaciq () 
{
  
int n, i;
  
double p;
  
  do
    
    {
      
cout <<
	"\n Vyvedete srochen vlog,za koito iskate da promenite lihvata:";
      
cin >> n;
    
}
  
while (n != 3 || n != 6 || n != 12);
  
cout << "\n Vyvedete lihva v realno chislo:";
  
cin >> p;
  
for (i = 0; i < N; i++)
    
    {
      
if (n == 3)
	A[i].M3.suma = A[i].M3.suma * p + A[i].M3.suma;
      
if (n == 6)
	A[i].M6.suma = A[i].M6.suma * p + A[i].M6.suma;
      
if (n == 12)
	A[i].M12.suma = A[i].M12.suma * p + A[i].M12.suma;
    
}

}


void
spravka () 
{
  
int i;
  char n[15];
  
cout << "\n Vyvedi ime:";
  
cin >> n;
  for (i = 0; i < N; i++)
    
    {
      
if (A[i].ime == n)
	disp (i);
    
}

}


void
izvejdane () 
{
  
int i, k, z;
  double temp;
  
for (i = 0; i < N; i++)
    
for (z = i + 1; z < N + 1; z++)
      
if (A[i].smetka > A[z].smetka)
	
	{
	  
temp = A[i].smetka;
	  
A[i].smetka = A[z].smetka;
	  
A[z].smetka = temp;
	
}
  
for (i = 0; i < N; i++)
    disp (i);

}


void
load () 
{
  
FILE * fp;
  int i;
  
if ((fp = fopen ("vlojiteli12.dat", "rb")) == NULL)
    
    {
      
cout << "\n EROR 404: File not found! ";
      
return;
    
}
  
if (fread (&top, sizeof (top), 1, fp) != 1)
    
    {
      
cout << "\n Error size";
      exit (1);
    
}
  
for (i = 0; i < top; i++)
    
if (fread (&A[i], sizeof (vlojiteli), 1, fp) != 1)
      
      {
	
cout << "\n Error reading structure!";
	exit (1);
      
}

}


 
 
void
save () 
{
  
FILE * fp;
  
int i;
  
if ((fp = fopen ("vlojiteli12.dat", "wb")) == NULL)
    
    {
      
cout << "\n Error saving file!";
      
return;
    
}
  
if (fwrite (&top, sizeof (top), 1, fp) != 1)
    
    {
      
cout << "\n Error w top";
      
exit (1);
    
}
  
for (i = 0; i < top; i++)
    
if (fwrite (&A[i], sizeof (vlojiteli), 1, fp) != 1)
      
      {
	
cout << "\n Error writing str!";
	
exit (1);
      
}
  
fclose (fp);

}

[Enoizat]

Hi, goshko1.
Perhaps the problem is your code is mainly a C code and this is a C++ forum. Many of our suggestions would change the face of your code.

To get a better help you could tell us:
- if this is an assignment (important!);
- if you have constrains (not to use std::vectors, keep the structs as they are, ...);
- if you know about std::strings, std::fstreams and std::vectors;
- if you know about classes and member functions (methods).

You could also provide a short example of the file "vlojiteli12.dat" to test your code.

What follows is another way to indent your code that could look more familiar to some of us.

#include <cmath>
#include <cstdio>       // <-- missing header
#include <iostream>


struct mesec {
    char data[12];
    double suma;
} ;


struct vlojiteli {
    char ime[25];
    char adres[20];
    mesec M3,
          M6,
          M12;
    double smetka;
} ;


void input ();
void vnasqne ();
void teglene ();
void aktualizaciq ();
void spravka ();
void izvejdane ();
int menu ();
void disp ();
void load ();
void save ();


constexpr int N { 30 };
vlojiteli A[N];
int top = 0;


int main ()
{
    int i;
    std::cout << "\nLoad from file";
    load ();
    do {
        i = menu ();
        switch (i)
        {
        case 1:
            input ();
            break;
        case 2:
            vnasqne ();
            break;
        case 3:
            teglene ();
            break;
        case 4:
            aktualizaciq ();
            break;
        case 5:
            spravka ();
            break;
        case 6:
            izvejdane ();
            break;
        case 7:
            save ();
            break;
        }
    } while (i != 8);
}


int menu ()
{
    int ch;
    std::cout << "MENU\n"
                 "1.Vyvejdane\n\n"
                 "2.Vnasqne po smetka\n\n"
                 "3.Teglene ot smetka\n\n"
                 "4.Aktualizaciq na lihvi\n\n"
                 "5.Spravka za vlojitel po Ime\n\n"
                 "6.Izvejdane na vsichki vlojiteli sortirani v spisyk\n\n"
                 "7.Syhrani fail\n\n"
                 "8.Izhod\n\n";
    do {
        std::cout << "\nIzbor: ";
        std::cin >> ch;
    } while (ch < 1 || ch > 8);
    return (ch);
}


void disp (int i)
{
    std::cout << "\nIme:" << A[i].ime
              << "\nAdress:" << A[i].adres
              << "\nM3 data:" << A[i].M3.data << "  M3 suma:" << A[i].M3.suma
              << "\nM6 data:" << A[i].M6.data << "  M6 suma:" << A[i].M6.suma
              << "\nM12 data:" << A[i].M12.data << "  M12 suma:" << A[i].M12.suma
              << "\nSmetka:" << A[i].smetka;
}


void input ()
{
    int i, n;
    do {
        std::cout << "Broi vlojiteli:";
        std::cin >> n;
    } while (n < 1 || n > N);

    fflush (stdin);

    for (i = top; i < top + n; ++i)
    {
        std::cout << "nIme:";
        std::cin >> A[i].ime;
        std::cout << "\nAdress:";
        std::cin >> A[i].adres;
        std::cout << "\nM3 data:";
        std::cin >> A[i].M3.data;
        std::cout << "\nM3 suma:";
        std::cin >> A[i].M3.suma;
        A[i].smetka += A[i].M3.suma;
        std::cout << "\nM6 data:";
        std::cin >> A[i].M6.data;
        std::cout << "\nM6 suma:";
        std::cin >> A[i].M6.suma;
        A[i].smetka += A[i].M6.suma;
        std::cout << "\nM12 data:";
        std::cin >> A[i].M12.data;
        std::cout << "\nM12 suma:";
        std::cin >> A[i].M12.suma;
        A[i].smetka += A[i].M12.suma;
    }
    top += n;
}


void vnasqne ()
{
    int n, p, i;
    do {
        std::cout << "\nIzberete nomer na vlojitel:";
        std::cin >> n;
    } while (n < 1 || n > N);

    std::cout << "\nIzberete vnoska za trimesechie,polovin godina ili edna godina:";
    std::cin >> p;
    if (p == 3)
    {
        for (i = n; i < n; ++i)
        {
            std::cout << "vyvedete data na vnasqne:";
            std::cin >> A[i].M3.data;
            std::cout << "vyvedete suma na vnasqne:";
            std::cin >> A[i].M3.suma;
            A[i].smetka += A[i].M3.suma;
        }
    }
    if (p == 6)
    {
        for (i = n; i < n; ++i)
        {
            std::cout << "vyvedete data na vnasqne:";
            std::cin >> A[i].M6.data;
            std::cout << "vyvedete suma na vnasqne:";
            std::cin >> A[i].M6.suma;
            A[i].smetka += A[i].M6.suma;
        }
    }
    if (p == 12)
    {
        for (i = n; i < n; ++i)
        {
            std::cout << "vyvedete data na vnasqne:";
            std::cin >> A[i].M12.data;
            std::cout << "vyvedete suma na vnasqne:";
            std::cin >> A[i].M12.suma;
            A[i].smetka += A[i].M12.suma;
        }
    }
}


void teglene ()
{
    int i, n;
    double s;
    do {
        std::cout << "\nIzberete nomer na vlojitel:";
        std::cin >> n;
    } while (n < 1 || n > N);

    std::cout << "\nIzberete sumata,koqto iskate da izteglite:";
    std::cin >> s;
    for (i = n; i < n; ++i)
    {
        if (s < A[i].smetka)
        {
            A[i].smetka = A[i].smetka - s;
        }
        else
        {
            std::cout << "Nqmate tolkowa pari!";
        }
    }
}


void aktualizaciq ()
{
    int n, i;
    double p;
    do {
        std::cout << "\nVyvedete srochen vlog,za koito iskate da promenite lihvata:";
        std::cin >> n;
    }  while (n != 3 || n != 6 || n != 12);

    std::cout << "\nVyvedete lihva v realno chislo:";
    std::cin >> p;

    for (i = 0; i < N; ++i)
    {
        if (n == 3)
        {
            A[i].M3.suma = A[i].M3.suma * p + A[i].M3.suma;
        }
        if (n == 6)
        {
            A[i].M6.suma = A[i].M6.suma * p + A[i].M6.suma;
        }
        if (n == 12)
        {
            A[i].M12.suma = A[i].M12.suma * p + A[i].M12.suma;
        }
    }
}


void spravka ()
{
    int i;
    char n[15];
    std::cout << "\nVyvedi ime:";
    std::cin >> n;
    for (i = 0; i < N; ++i)
    {
        if (A[i].ime == n) {
            disp (i);
        }
    }
}


void izvejdane ()
{
    int i, k, z;
    double temp;
    for (i = 0; i < N; ++i)
    {
        for (z = i + 1; z < N + 1; ++z)
        {
            if (A[i].smetka > A[z].smetka)
            {
                temp = A[i].smetka;
                A[i].smetka = A[z].smetka;
                A[z].smetka = temp;
            }
        }
    }
    for (i = 0; i < N; ++i) {
        disp (i);
    }
}


void load ()
{
    std::FILE * fp;
    int i;
    if ((fp = fopen ("vlojiteli12.dat", "rb")) == NULL)
    {
        std::cout << "\nEROR 404: File not found! ";
        return;
    }
    if (fread (&top, sizeof (top), 1, fp) != 1)
    {
        std::cout << "\nError size";
        exit (1);
    }
    for (i = 0; i < top; ++i)
    {
        if (fread (&A[i], sizeof (vlojiteli), 1, fp) != 1)
        {
            std::cout << "\nError reading structure!";
            exit (1);
        }
    }
}


void save ()
{
    std::FILE * fp;
    int i;
    if ((fp = fopen ("vlojiteli12.dat", "wb")) == NULL)
    {
        std::cout << "\nError saving file!";
        return;
    }
    if (fwrite (&top, sizeof (top), 1, fp) != 1)
    {
        std::cout << "\nError w top";
        exit (1);
    }
    for (i = 0; i < top; ++i)
    {
        if (fwrite (&A[i], sizeof (vlojiteli), 1, fp) != 1)
        {
            std::cout << "\nError writing str!";
            exit (1);
        }
    }
    fclose (fp);
}