Memory game

[clerkolleseum]

I was trying to create a memory type of game here with 8 by 8 totaling 64. What I'm trying to do here is to have 2 sets of pairs in the board from 1 - 32. I used the rand to generate random integer for every column and row however I do notice that some numbers appear more than twice and some only once or none. What can I do to limit these numbers to make them appear exactly two times?

#include <iostream>;
using namespace std;
void memorygame();

int main(){
    memorygame();
    system ("pause");
    return 0;
      }

void memorygame(){
  int board[8][8];
	for (int i = 0; i < 8; i++){
		cout << endl;
		for (int j = 0; j < 8; j++){
			grid[i][j] = 1 + (rand() % 32);
			cout << board[i][j] << " ";
		}
	}
	cout << endl;
      }

[EtDecius]

If you want to populate the array with number pairs, you will need a way to track which numbers have been used.

One option is to create a list of ints that holds two of each number from 1 to 32. For example, using a vector:

vector<int> tiles;
for (int i = 0; i < 32; ++i)
{
    tiles.push_back(i+1);
    tiles.push_back(i+1);
}

Once you have your list, you can use rand() to choose an index from 0 to tiles.size(), insert the value stored at the index into your board, then erase that element from tiles so you don't repeat it later. I used a vector instead of an array because it's easier to remove elements from the middle.

No doubt there are other ways to achieve your goal. I suspect in any solution, you'll need to track what integers have been added -or- what integers still need to be added.

[Nico]

Hello,

To do that you have two options:
- You can keep track of which values are already in the board.
- You can limit the values that the computer can choose from to a set of values and make sure that set contains exactly two values of each to start with.

Personally I would go for the second option. That could look something like this:

#include <iostream>
#include <vector>       // required to work with vectors
#include <algorithm>    // required to randomize a vector

void memorygame(int boardsize);

int main()
{
    memorygame(8);
    system ("pause");
    return 0;
}

void memorygame(int boardsize)
{
    std::vector<int> cards;
    for (int i=0; i<(boardsize*boardsize)/2; i++)
    {
        cards.push_back(i+1);
        cards.push_back(i+1);
    }
    // You now have a vector with 64 values (1 to 32 all twice).
    // using built-in random generator to shuffle all the cards:
    std::random_shuffle ( cards.begin(), cards.end() );
    // You now have a randomized vector with 64 values, (1 to 32 all twice).
    // Lets put them in the board.
    int board[boardsize][boardsize];
    for (int i = 0; i < boardsize; i++)
    {
		std::cout << std::endl << std::endl;
		for (int j = 0; j < boardsize; j++)
		{
			board[i][j] = cards.back();      // places the last value from the vector in your grid.
			cards.pop_back();               // removes the last value from the vector
            std::cout << board[i][j] << "\t";
        }
    }
    std::cout << std::endl;
}

I hope that helps your game.

Kind regards, Nico

[clerkolleseum]

Hmm I never thought about using vectors for that. I'm still not that used to using vector yet but I will try it. Thks guys.