A 1-script snake game implemented in object-less c++

Snake.cpp

// Snake.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include <iostream>
#include <conio.h>
#include <Windows.h>

using namespace std;

bool gameOver;
const int width = 20;
const int height = 20;
int x, y, fruitX, fruitY, score;

int tailX[width * height], tailY[width * height];
int nTail;

enum eDirection { STOP = 0, LEFT, RIGHT, UP, DOWN };
eDirection dir;

void Setup()
{
	gameOver = false;
	dir = STOP;
	x = width / 2;
	y = height / 2;

	fruitX = rand() % width;
	fruitY = rand() % height;
	score = 0;
}

void Draw()
{
	system("cls");

	for (int i = 0; i < width + 2; i++)
	{
		cout << "#";
	}

	cout << endl;

	for (int i = 0; i < height; i++)
	{
		cout << "#";

		for (int j = 0; j < width; j++)
		{

			if (i == y && j == x)
			{
				cout << "O";
			}
			else if (i == fruitY && j == fruitX)
			{
				cout << "F";
			}
			else
			{
				bool printedTail = false;
				for (int k = 0; k < nTail; k++)
				{
					if (j == tailX[k] && i == tailY[k])
					{
						cout << "o";
						printedTail = true;
						break;
					}
				}

				if (!printedTail)
				{
					cout << " ";
				}
			}
		}
		cout << "#";
		cout << endl;
	}

	for (int i = 0; i < width + 2; i++)
	{
		cout << "#";
	}

	cout << endl << "Score: " << score;
}

void Input()
{
	if (_kbhit())
	{
		switch (_getch())
		{
			case 'a':
				if (dir != RIGHT)
				{
					dir = LEFT;
				}
				break;
			case 'd':
				if (dir != LEFT)
				{
					dir = RIGHT;
				}
				break;
			case 'w':
				if (dir != DOWN)
				{
					dir = UP;
				}
				break;
			case 's':
				if (dir != UP)
				{
					dir = DOWN;
				}
				break;
			case 'x':
				gameOver = true;
				break;
		}
	}
}

void Logic()
{
	if (nTail > 0)
	{
		for (int i = nTail - 1; i > 0; i--)
		{
			tailX[i] = tailX[i - 1];
			tailY[i] = tailY[i - 1];
		}

		tailX[0] = x;
		tailY[0] = y;
	}

	switch (dir)
	{
	case LEFT:
		x--;
		break;
	case RIGHT:
		x++;
		break;
	case UP:
		y--;
		break;
	case DOWN:
		y++;
		break;
	default:
		break;
	}

	if (x == fruitX && y == fruitY)
	{
		score++;
		fruitX = rand() % width;
		fruitY = rand() % height;
		nTail++;
	}
	
	if (x < 0)
	{
		x = width - 1;
	}
	else if (x >= width)
	{
		x = 0;
	}

	if (y < 0)
	{
		y = height - 1;
	}
	else if (y >= height)
	{
		y = 0;
	}

	for (int k = 0; k < nTail; k++)
	{
		if (x == tailX[k] && y == tailY[k])
		{
			gameOver = true;
			break;
		}
	}
}

int main()
{
	Setup();

	while (!gameOver)
	{
		Draw();
		Input();
		Logic();
		Sleep(100);
	}

    return 0;
}