Game of Life improvement

Question

I have finished my code for Conway's Game of Life. I am looking for any advice on how to improve it. I am a C++ beginner, so I used only basic libraries. I am accepting all suggestions.

/*
Author: Stevan Milic
Date: April 2018
Class: COSC 1560
Description: Game Of Life
*/
#include <iostream>
#include <cstdlib>  // Library needed for CLS command
#include <iomanip> 
using namespace std;


const int boardsize = 10;

void Display(bool board[boardsize + 1][boardsize + 1]) 
{
    for (int x = 1; x < boardsize; x++) 
    {
        for (int y = 1; y < boardsize; y++) 
        {
            if (board[x][y] == true) 
            {
                cout << " * ";
            }
            else 
            {
                cout << " - ";
            }
            if (y == boardsize - 1) 
            {
                cout << endl;
            }
        }
    }
}
// Copying the board in order to compare the existing cells
void CopyBoard(bool board[boardsize + 1][boardsize + 1], bool board2[boardsize + 1][boardsize + 1]) 
{
    for (int x = 0; x < boardsize; x++) 
    {
        for (int y = 0; y < boardsize; y++) 
        { 
            board2[x][y] = board[x][y]; 
        }
    }
}
//Calculates function to determine if the cell is alive or dead
void Calc(bool board[boardsize + 1][boardsize + 1]) 
{
    bool board2[boardsize + 1][boardsize + 1] = {};
    CopyBoard(board, board2);
    for (int x = 1; x < boardsize; x++) 
    {
        for (int y = 1; y < boardsize; y++) 
        {
            int alive = 0;
            for (int z = -1; z < 2; z++) 
            {
                for (int t = -1; t < 2; t++) 
                {
                    if (!(z == 0 && t == 0)) 
                    {
                        if (board2[x + z][y + t]) 
                        { 
                            alive++; 
                        }
                    }
                }
            }
            if (alive < 2) 
            { 
                board[x][y] = false; 
            }
            else if (alive == 3) 
            { 
                board[x][y] = true; 
            }
            else if (alive > 3) 
            { 
                board[x][y] = false; 
            }
        }
    }
}

int main() 
{

    //const int boardsize = 10;
    bool board[boardsize + 1][boardsize + 1] = {};

    // Starting cells
    board[5][4] = true;
    board[5][5] = true;
    board[5][6] = true;
    board[4][4] = true;
    board[4][5] = true;
    board[4][6] = true;
    board[3][4] = true;
    board[3][5] = true;
    board[3][6] = true;

    while (true) 
    {
        Display(board);     // Displaying function
        Calc(board);        // Calculating function
        system("CLS");      // Clearing the Screen
    }
}

Answer 1

I'm unsure what you mean by saying "improve the user interface". AFAIK Game of life doesn't have much of a user interface as it's a simulation that only displays the grid and whatever happens on it.
However there are some other things that can definitely be improved.

• Don't use using namespace std

• Generally functions in C++ are lowercase

• Think about better variable names.
  x and y might be acceptable but t and z are probably not the best names.

• Prefer using \n over std::endl

• Prefer prefix over postfix operator

• Don't compare to booleans. Instead do if (condition) and
  if (!condition).

• You might want to use vectors for your board instead of arrays.

• Don't use global variables (which you don't need when you're using vectors)

• There is another way to write an endless loop which is a for loop without conditions for (;;) (read as forever).
  Which one is better is highly opinion based however.

• Your cluster of for loops is quite hard to grasp. It would improve readability and understanding if you break it up into smaller parts. For example you could write a function to iterate over the cells and for every cell call another function that checks the adjacent ones for live cells.