Histogram issues

Hey everyone how's it going I'm new here so it's nice to meet all of you. Well I have a question I'm supposed to write a histogram program where the uses inputs a set of numbers, followed by a -1. this would output a sideways histogram so for example is the use iputs 1, 2, 3, -1. the result would be
*
**
***
For some reason I can't seem to get this I've actually tried everything so this is really annoying me to be honest. I think I'm in the right directoin with the code but to be honest I think it's completely wrong. Heres my code as is

Code:

#include <iostream>
using namespace std;

void printHistogram(int ar[], int size);

int main( )
{
    const int SIZE = 5;
    int HistoGram[SIZE];
    
    cout << "Enter a list of positive numbers.\n"
         << "Place a -1 at the end.\n";

    int next;
    cin >> next;
    while (next > 0)
    
    printHistogram(int ar[], int size)
   
    system("pause");
    return 0;
}

void printHistogram(int ar[], int size)
{
  for (int i = 0; i < size; i++) 
  {
    int numStars = ar[i];
    for (int j = 0; j < numStars; j++)
      cout << '*';
    cout << endl;
  }
}

This just creates an infinite loop of *. Anyone think they can give me some help. Anything would be greatly appreciated. Sorry if this is kind of a fairly dum question. but thanks in advanced.

There's no way the code you posted would compile, what with that "printHistogram(int ar[], int size)" in the middle of it all.

Were you planning to do something with the data you read in? At the moment, you're just ignoring it.