Need help passing an array of structure to a function - c++

Question

So, I am currently studying at school and I need to do my homework. I am a beginner in C++ and somehow the compiler shows me an error in my code. Basically, I have a .txt file where the data is stored.
The .txt file looks something like this:
5
Petras 23.25 10.50
Rimas 125.40 1.20
Romas 55.00 1.00
Jurgis 1000.90 0.25
Algis 15.00 25.50
The first line shows how much people in the list we have, so I created integer n.
Next we have a list of people. The list tells the name of the person, how much money he has in different currency, and shows the rate of exchange to euros.
And the problem is that I am trying to find the sum of the money they have in Euros. This is my code.
#define USE_MATH_DEFINES
#include <iostream>
#include <fstream>
#include <iomanip>
#include <cmath>
using namespace std;
const int Cn = 100;
const int Cname = 15;
int n;
struct listofpeople {
string name;
double MoneyInOtherCurrency;
double RateOfExchange;
double MoneyInEuros;
};
listofpeople A[Cn + 1];
void data();
void ChangeCurrency();
double sum(double C[], int m);
int main () {
data();
ChangeCurrency();
cout << sum(A[].MoneyInEuros, n);
return 0;
}
//-------------------------------------------------------
void data(){
ifstream is ("U2duom.txt");
is >> n;
char symbols[Cname + 1];
for(int i = 1; i <= n; i++){
is.ignore(80, '\n');
is.get(symbols, Cname);
A[i].name = symbols;
is >> A[i].MoneyInOtherCurrency;
is >> A[i].RateOfExchange;
}
}
//----------------------------------------------------------
void ChangeCurrency(){
for(int i = 1; i <= n; i++){
A[i].MoneyInEuros = A[i].MoneyInOtherCurrency*A[i].RateOfExchange;
cout << A[i].name << " " << A[i].MoneyInEuros << " " <<
A[i].MoneyInOtherCurrency << " " << A[i].RateOfExchange << endl;
}
}
//---------------------------------------------------------------
double sum(double C[], int m){
double a = 0;
for(int i = 1; i <= m; i++){
a= a + C[i];
}
return a;
}
And the problem is that the compiler shows me an error in the line where i try to print the sum. Could anyone help me? Thanks.
EDIT:
My compiler shows this error:
error: expected primary-expression before ']' token
If I specify array elements I want to use, for example:
sum(A[n].MoneyInEuros, n);
The compiler shows this error:
cannot convert 'double' to 'double*' for argument '1' to 'double
sum(double*, int)'

Answer 1

double sum(double C[], int m); takes an array of doubles, but you only have an array of listofpeople. This doesn't work.
You have to change sum so that it takes an array of listofpeople, or you change your data structure from a Structure Of Arrays to an Array of Structures (better for performance, more complex to handle).
Typically, sum requires reimplementing:
double sum(listofpeople *s, int m);
Be aware that in C++, we don't use the [] notation for types.