Would you care to help me c++?

So I'm supposed to write a program that uses the following functions:

Fill_array() takes as arguments the name of an array of double values and an array size. It

prompts the user to enter double values to be entered in the array. It ceases taking input when

the array is full or when the user enter a negative number, and it returns the actual number of

entries.

Show_array() takes as arguments the name of an array of double values and an array size and

displays the contents of the array.

Reverse_array() takes as arguments the name of an array of double values and an array size and

reverses the order of the values stored in the array.

The program should use these functions to fill an array, show the array, reverse the array, show

the array, reverse all but the first and last elements of the array, and then show the array.

Here is what i have so far:

#include <iostream>

using namespace std;

int fill_array(double *pt,int size);

void show_array(double *pt, int size);

int reverse_array(double *pt, int size);

int main()

{

double amat[10];

int n;

n = fill_array(amat,10);

show_array(amat,10);

n = reverse_array(amat,10);

show_array(amat,10);

char x;

cout << "\nPress any key and Enter to exit";

cin >> x;

return 0;

}

int fill_array(double *pt,int size)

{

int i;

cout << "Enter " << size << " values\n";

for(i=0;i<size;i++)

{

cin >> pt[i];

}

return i;

}

void show_array(double *pt,int size)

{

int i;

cout << "\n\nArray values:\n";

for(i=0;i<size;i++)

cout << pt[i]<< "\t";

return;

}

int reverse_array(double *pt, int size)

{

int i;

int swap;

for(i=0;i<--size;i++) //increment i and decrement size until they meet each other

{

swap=pt[i];

pt[i]=pt[size];

pt[size]=swap;

}

return i;

}

The main problems that I have is that I don't know how to make the array stop taking values when a negative number is entered and I don't know how to do the last thing where it wants me to keep the first and last number but reverse the others.

Please help.