New, Help.

[Rento]

Hi, I started learning from this book and I am trying to generate a random number from 1-100. The result is generated in a line and I am trying to make it in a 10x10 grid. It says use something like the GRID_SIZE method but im not quite sure on how to use it

 #include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

void InitRand() {
	srand((unsigned int)time(NULL));
}

int main()
{
	InitRand();
	const int GRID_SIZE = 10;
	int grid[GRID_SIZE][GRID_SIZE];

	int k = 0;
	while (k++ < 100) {
		int r = (rand() % 100) + 1;
		cout << r << " ";
		}
	
	system("pause");
	return 0;

}

[Thomas1965]

Normally you would have two nested loops when dealing with a grid.
One loop for the rows and one loop for the columns.

for (int row = 0; row < GRID_SIZE; row++)
  for (int col = 0; col < GRID_SIZE; col++)
  {
     // use grid[row][col];
  }

The 2d array is very common, so devote some time to it.

[Manga]

#include <iostream>
#include <cstdlib>
#include <ctime>
using namespace std;

void InitRand() {
	srand((unsigned int)time(NULL));
}

int main()
{
	InitRand();
	const int GRID_SIZE = 10;
	int grid[GRID_SIZE][GRID_SIZE];

	for (int i = 0; i < 10; i++) {
		for (int j = 0; j < 10; j++) {
			grid[i][j] = (rand() % 100) + 1;
			cout << grid[i][j] << " ";
			if (j == 9) {
				cout << endl;
			}
		}
	}

	

	system("pause");
	return 0;

}

[keskiverto]

@Manga: What are these magick 10 on lines 16 and 17?
(The loop by Thomas is more expressive.)

You don't need any array (or even nested loop), if you simply want to show numbers:

#include <iostream>
#include <iomanip>
#include <random>
#include <chrono>

int main()
{
  unsigned seed1 = std::chrono::system_clock::now().time_since_epoch().count();
  std::mt19937 generator( seed1 ); // insufficient seed
  std::uniform_int_distribution<int> distribution( 1, 100 );

  constexpr int GRID_SIZE = 10;

  for (int i=0; i < GRID_SIZE*GRID_SIZE; ++i ) {
    int number = distribution(generator);
    std::cout << std::setw(4) << number;
    if ( i % GRID_SIZE + 1 == GRID_SIZE ) std::cout << '\n';
  }
}

[Manga]

OP has a 2d array. I thought the numbers should fit inside the array for safe keeping. As for the magick 10... That is just how I roll!

Ok I can't back that up. It was a result of me trying to type too fast. I wanted to finish and post before anyone else. But that Thomas is quick on the draw!