euler_file.cpp

// find the largest product of 4 of the numbers in any direction (up,
// down, left, right, diagonal) in my output I get the file location
// "0xbfca024c" repeated

#include <iostream>
#include <fstream>
using namespace std; 
 
int main ()
{
  int maxValue;
  int value  = -9876;
  int row, col;
  ifstream file;
  
  file.open("greatest_product.txt");
  file >> row >> col;
 
  int array20 [row][col];
  
  cout << "File contents (by way of array):" << endl;
  for (int i= 0; i < row; i++)
  {
    for (int j = 0; j < col; j++)
    {
      file >> array20[i][j];
      cout << array20[i][j] << " ";
    }
  }
  cout << endl;
  cout << "Value: " << value << endl;
  
  cout << "Address of array: " << endl;
  cout << array20 << endl;

  cout << "Values in array: " << endl;
  // here we have to iterate through the cells in the array. Unlike
  // Python, we can't just say 'print out this array'. C and C++
  // aren't smart, at all.
  for (int i=0; i < row; i++) {
    for (int j=0; j < col; j++) {
      cout << "array cell " << i << ", " << j << ": " << array20[i][j] << endl;
    }
  }
  return 0;
}

greatest_product.txt

3 3
1 2 3
4 5 6
7 8 9

output.txt

File contents (by way of array):
1 2 3 4 5 6 7 8 9 
Value: -9876
Address of array: 
0x7fff566416c0
Values in array: 
array cell 0, 0: 1
array cell 0, 1: 2
array cell 0, 2: 3
array cell 1, 0: 4
array cell 1, 1: 5
array cell 1, 2: 6
array cell 2, 0: 7
array cell 2, 1: 8
array cell 2, 2: 9