Help for code on rand and board

[alexandrap98]

I am quite stuck on a homework assignment. I have a function that has to recognize 3 boards and randomly display one and if the user gets the answer wrong then they will display another board<- this is in beginGame(). I do not know what code to put and how it would randomly display. Any help would be appreciated. I am imagining there are multiple things wrong with my current program, but im just fixated on this one area and unable to think. And I have to use only the three libraries.


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

int beginGame(int playedBoard[]);
void displayBoard(int board[][3]);
bool testWinner(int ans, int boardNum, int ansBoard[]);
void instructions();

int main()
{
int board1[4][3] = { 38, 11, 83,
15, 6, 33,
10, 2, 20,
86, NULL, 95 };
int board2[4][3] = { 28, 10, 55,
89, 17, 98,
22, 4, 31,
60, NULL, 78 };
int board3[4][3] = { 90, 9, 45,
66, 12, 48,
34, 7, 70,
44, NULL, 26 };

int ansArray[3] = { 14, 15, 8 };
int usedBoards[3] = { NULL};
int answer, guess;
int win = 0;
int tries = 0;


instructions();

cout << " Enter Guess or 0 to exit" << endl;
cin >> guess;


}


int beginGame(int playedBoard[])
{
int randomNum = (rand() % (3-1 + 1)) + 1;
if playedBoard[r] == 0;
return r;


return randomNum;
}

void displayBoard(int board[][3])
{


}

bool testWinner(int ans, int boardNum, int ansBoard[])
{


}

[JLBorges]

Something along these lines, perhaps:

#include <iostream>
#include <iomanip>
#include <cstdlib>
#include <ctime>

const int NROWS = 4 ;
const int NCOLS = 3 ;
using board = int[NROWS][NCOLS] ;

void display_board( const board& brd )
{
    for( const auto& row : brd )
    {
        for( int v : row )
        {
            if( v == 0 ) std::cout << " NULL " ;
            else std::cout << std::setw(4) << v << "  " ;
        }
        std::cout << '\n' ;
    }
}

int display_random_board( const board brds[], int num_boards )
{
    if( num_boards < 1 ) return num_boards ;

    const int random_board_number = std::rand() % num_boards ;
    std::cout << "board #" << random_board_number << "\n--------\n" ;
    display_board( brds[random_board_number] ) ;
    return random_board_number ;
}

void begin_game( board brds[], int num_boards )
{
    [[maybe_unused]] const int chosen_board = display_random_board( brds, num_boards ) ;

    // ...
}

int main()
{
    std::srand( std::time(nullptr) ) ;

    const int NBOARDS = 3 ;
    board game_boards[NBOARDS] =
    { { 38, 11, 83, 15, 6, 33, 10, 2, 20, 86, 0, 95 }, // note: brace elision
      { 28, 10, 55, 89, 17, 98, 22, 4, 31, 60, 0, 78 },
      { 90, 9, 45, 66, 12, 48, 34, 7, 70, 44, 0, 26 }
    };

    begin_game( game_boards, NBOARDS ) ;
}

http://coliru.stacked-crooked.com/a/eaae5b3f8e9da4ec

[Peter87]

NULL is meant for pointers. If you mean zero you should write 0, or use some constant with the value zero, but not NULL.