C++ Program: Connect 4 Game I need help fixing undefined identifiers in my code. connect4.cc // The main game loop for C

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C++ Program: Connect 4 Game
I need help fixing undefined identifiers in my code.
connect4.cc
// The main game loop for Connect 4.
#include <ncurses.h>
#include <iostream>
#include <random>
#include <utility>
#include "ai.h"
#include "game.h"
#include "players.h"
using namespace std;
// *** Utility functions only used in this file. ***
// Switches from player 1 to player 2 and vice-versa.
int SwitchPlayer(int player);
// Get a move from the human. Updates UI to show column
selection.
bool GetPlayerMove(const Board &board, int &move);
// Plays a single game.
int PlayGame(pair<PlayerType, PlayerType> players, bool
silent);
int main(int argc, char **argv) {
srand(time(0));
pair<PlayerType, PlayerType> players;
if (argc == 3) {
players = make_pair(GetPlayerType(argv[1]),
GetPlayerType(argv[2]));
} else if (argc == 1) {
players = make_pair(PlayerType::kHuman,
PlayerType::kRandom);
} else {
cerr << "Usage: ./connect4 [player1] [player2]" <<
endl;
return 1;
}
// Show the screen if either player is a human.
bool silent = true;
if (players.first == PlayerType::kHuman ||
players.second == PlayerType::kHuman) {
silent = false;
initscr();
cbreak();
noecho();
keypad(stdscr, TRUE);
}
if (silent) {
// The pit. Two AIs fighting each other.
int player1_wins = 0;
int player2_wins = 0;
int draws = 0;
for (int i = 0; i < 1000; ++i) {
int winner = PlayGame(players, silent);
if (winner == 1) {
player1_wins += 1;
} else if (winner == 2) {
player2_wins += 1;
} else if (winner == 0) {
draws++;
}
}
cout << "Player 1 wins: " << player1_wins <<
endl;
cout << "Player 2 wins: " << player2_wins <<
endl;
cout << "Draws: " << draws << endl;
} else {
// Play a single game Human vs. AI.
PlayGame(players, silent);
}
// Wait for any key press.
if (!silent) {
getch();
endwin();
}
return 0;
}
// Returns false if the user wants to exit.
bool GetPlayerMove(const Board &board, int &move) {
int ch;
while (true) {
// User Move
ch = getch();
if (ch == KEY_RIGHT && move <= 5) {
move += 1;
} else if (ch == KEY_LEFT && move > 0) {
move -= 1;
} else if (ch == ' ') {
return true;
} else if (ch == 'q') {
return false;
}
DrawBoard(board, move);
}
}
int SwitchPlayer(int player) {
if (player == 1) return 2;
if (player == 2) return 1;
throw;
}
int PlayGame(std::pair<PlayerType, PlayerType> players,
bool silent) {
Board board;
int current_player = 1;
InitializeBoard(board);
int player_move = 0;
// Loop ends if the game ends or GetPlayerMove returns
false.
while (true) {
if (!silent) DrawBoard(board, player_move);
if (Winner(board) != 0) {
break;
}
PlayerType player_type;
if (current_player == 1) {
player_type = players.first;
} else if (current_player == 2) {
player_type = players.second;
} else {
throw;
}
// Kept separate from player_move to avoid updating UI.
int move_to_make;
switch (player_type) {
case PlayerType::kHuman:
if (!GetPlayerMove(board, player_move)) {
printw("Game over.");
return Winner(board);
}
move_to_make = player_move;
break;
case PlayerType::kRandom:
move_to_make = RandomAgent(board, current_player);
break;
case PlayerType::kFirst:
move_to_make = FirstOpenAgent(board, current_player);
break;
case PlayerType::kInvalid:
default:
throw;
}
bool result = Drop(board, current_player, move_to_make);
if (result) current_player = SwitchPlayer(current_player);
}
int winner = Winner(board);
if (!silent) {
if (winner == 1) {
printw("Player 1 wins!");
} else if (winner == 2) {
printw("Player 2 wins!");
} else if (winner == -1) {
printw("Draw.");
} else {
printw("Game over.");
}
}
return winner;
}
PROBLEMS
identifier "Board" is undefined
identifier "PlayerType" is undefined
identifier "Drop" is undefined
identifier "Winner" is undefined
identifier "InitializeBoard" is undefined
identifier "DrawBoard" is undefined
Let me know if more files are needed