Here's the C++ program to print Pascal's Triangle up to N rows:

```
#include <iostream>
using namespace std;

int main() {
  int n;
  cout << "Enter the number of rows: ";
  cin >> n;

  int arr[n][n];
  // initialize first two rows
  arr[0][0] = 1;
  arr[1][0] = 1;
  arr[1][1] = 1;

  for(int i=2; i<n; i++) {
    arr[i][0] = 1; // set first element to 1
    for(int j=1; j<=i; j++) {
        // calculate each element using the formula
        arr[i][j] = arr[i-1][j-1] + arr[i-1][j];
    }
  }

  // print the triangle
  for(int i=0; i<n; i++) {
    for(int j=0; j<=i; j++) {
        cout << arr[i][j] << " ";
    }
    cout << endl;
  }

  return 0;
}
```

The output will be in the form of Pascal's Triangle up to the desired number of rows.
Programma C++ per stampare il triangolo di Pascal. Prende come input N e lo visualizza in STD_OUT.