#include <cstdio>
#include <iostream>
#include <fstream>
#include <string>
#include <ctime>
#include <conio.h>
#include <dos.h>
#include <Windows.h>
#include <time.h>

using namespace std;

int const weight = 20;
int const leight = 20;
int field[weight][leight];
int dir;
int snake_x = weight / 2;
int snake_y = leight / 2;
bool game_over = false;
int tail = 3;
int snake_olx;
int snake_oly;

void generate_food()
{
    srand(time(NULL));
    int food_x = rand() % (weight - 2) + 1;
    int food_y = rand() % (leight - 2) + 1;
    field[food_x][food_y] = -2;
}

void init_field()
{
    for (int i = 0; i < weight; i++)
    {
        field[0][i] = -1;
        field[leight - 1][i] = -1;
    }

    for (int i = 1; i < leight - 1; i++)
    {
        for (int j = 1; j < weight - 1; j++)
        {
            field[i][0] = -1;
            field[i][j] = 0;
            field[i][weight - 1] = -1;
        }
    }
    field[snake_x][snake_y] = 1;
    generate_food();

}



char get_field_char(int key) {
    char ch;
    switch (key)
    {
    case -1:
        ch = '#';
        break;
    case 0:
        ch = ' ';
        break;
    case -2:
        ch = '@';
        break;
    /*case 3:
        ch = '^';
        break;
    case 4:
        ch = '|';
        break;
    */
    default:
        break;
    }
    return ch;
}

void input()
{
    if (_kbhit())
    {
        int ch = _getch();
        switch (ch)
        {
        //case 'w':
        case 230:
            dir = 1;
            break;
        //case 'a':
        case 228:
            dir = 2;
            break;
        //case 's':
        case 235:
            dir = 3;
            break;
        //case 'd':
        case 162:
            dir = 4;
            break;
        default:
            break;
        }
    }
}

void logic()
{
    snake_olx = snake_x;
    snake_oly = snake_y;
    switch (dir)
    {
    case 1:
        snake_x--;
        snake_olx = snake_x;
        break;
    case 2:
        snake_y--;
        break;
    case 3:
        snake_x++;
        break;
    case 4:
        snake_y++;
        break;
    default:
        break;
    }
}

void update_field()
{
    if (field[snake_x][snake_y] == -1)
    {
        game_over = true;
    }
    else if (field[snake_x][snake_y] == -2)
    {
        generate_food();
        tail++;
        field[snake_olx][snake_oly] = tail;
        field[snake_x][snake_y] = tail++;
    }
    /*else if (field[snake_x][snake_y] > 2)
    {
        game_over = true;
    }*/

    for (int i = 1; i < leight - 1; i++)
    {
        for (int j = 1; j < weight - 1; j++)
        {
            if (_kbhit())
            {
                if (field[i][j] > 0)
                {
                    field[i][j] --;
                }
            }
        }
    }
}

void print_field()
{
    for (int i = 0; i < weight; i++)
    {
        for (int j = 0; j < leight; j++)
        {
            if (field[i][j] > 0)
            {
                cout << '^';
            }
            else
            cout << get_field_char(field[i][j]);
        }
        cout << endl;

    }
}

int main()
{
    init_field();
    while (game_over != true)
    {
        input();
        logic();
        print_field();
        update_field();
        system("cls");
        Sleep(10);
    }
    return 0;
}