struct + functions code breaks - c++

Question

There is a problem with the code and i could not find it.
i was asked to write a money struct and use functions to manipulate it.
but the code did not work for any function. i tried couting
the array of structers and it came out nicely, for any missing info
please leave a comment and i'll reply shortly.
Money.txt
2
12 20
13 40
#include <iostream>
#include <fstream>
using namespace std;
struct Money { //declaring structure
int dollars;
int cents;
};
Money addMoney(Money *p[], int n) { //adds money data
Money cash{ 0,0 };
int i;
for (int j = 0; j < n; j++) {
cash.dollars = cash.dollars + p[j]->dollars;
cash.cents = cash.cents + p[j]->cents;
}
if (cash.cents >= 100) //100cents = 1 dollar
{
i = (cash.cents) / 100;
cash.dollars = cash.dollars + i;
i = (cash.cents) % 100;
cash.cents = i;
}
return cash;
}
void printMoney(Money *p[], int n) { //printing money data
for (int i = 0; i < n; i++) {
cout << "Dollars: " << p[i]->dollars << endl;
cout << "Cents: " << p[i]->cents << endl;
}
}
Money maxMoney(Money *p[], int n) {
Money cash;
cash.dollars = p[0]->dollars;
cash.cents = p[0]->cents;
for (int i = 0; i < n; i++)
{
if ((p[i]->dollars)>=(cash.dollars))
if ((p[i]->cents)>(cash.cents))
{
cash.dollars = p[i]->dollars;
cash.cents = p[i]->cents;
}
}
return cash;
}
void main() {
Money cash;
ifstream mycin("money.txt");
if (mycin.fail())
cout << "Enable to open file";
int x;
mycin >> x;
Money *arr = new Money[x];
for (int i = 0; i < x; i++)
{
mycin >> arr[i].dollars;
mycin >> arr[i].cents;
}
cout << "The values in money.txt are: ";
printMoney(&arr, x);
cash = addMoney(&arr, x);
cout << "These values added are :";
cout << cash.dollars << " Dollars and " << cash.cents << " cents" << endl;
cash = maxMoney(&arr, x);
cout << "Maximum value is :";
cout << cash.dollars << " Dollars and " << cash.cents << " cents" << endl;
}

Answer 1

These functions appear to accept an array of pointers to Money, but you're trying to use them with an array of Money.
I suggest you play with arrays of pointers to simpler types (like int) until you're comfortable with the concept, before you attempt it with Money.

Answer 2

This sounds a lot like homework so I'm not posting a full solution, but I will explain what appears to be the misunderstanding and give you some pointers.
First you declare your data structure as an array of Money structures, e.g. a continuous series of blocks of memory containing the Money struct, the first of which is pointed to by "arr" in your main program.
But then, in the rest of the program (functions) you seem to expect the data structure being used to be an array of Money pointers. See the difference? They're not the same and this will not work as is. You have to be consistent.
Either you're dealing with an array of structs, in which case you pass effectively a single, simple Money* to your functions everywhere (and you dereference with . not ->)
Or you're dealing with an array of pointers, in which case you pass effectively a pointer to a (Money pointer) and you dereference with -> as you've done. But then you also have to allocate each Money struct individually when you're reading them in in the main program. That is to say, allocating memory for the array of pointers does not automatically allocate memory for each Money pointer reference in the array of pointers and so you need to do this for each entry you're reading in.
So, as you should hopefully now realise, there's multiple ways to fix your program.
As per your later comment, given that the function signatures need to stay as-is, I would suggest you work with an array of Money pointers.
Money** arr = new Money*[x]
Then you need to add a line to your loop during reading, to actually make each Money * point to a Money struct:
for (int i = 0; i < x; i++)
{
arr[i] = new Money
...
Finally then, because "arr" is now a pointer to a pointer to Money, you can directly pass it to your functions, so calling them are just for example:
printMoney(arr, x);