Logo Language

#include <iostream>

#define CANVAS_WIDTH  20
#define CANVAS_HEIGHT 20

class Direction {
private:
    enum direction_t {
        UP,
        DOWN,
        LEFT,
        RIGHT
    } _dir;

public:
    Direction(direction_t dir = DOWN)
        : _dir(dir)
    {
    }

    Direction& turn_left()
    {
        switch (_dir) {
        case UP:
            _dir = LEFT;
            break;
        case DOWN:
            _dir = RIGHT;
            break;
        case LEFT:
            _dir = DOWN;
            break;
        case RIGHT:
            _dir = UP;
            break;
        default:
            throw std::runtime_error("Unknown direction");
        }
        return *this;
    }

    Direction& turn_right()
    {
        switch (_dir) {
        case UP:
            _dir = RIGHT;
            break;
        case DOWN:
            _dir = LEFT;
            break;
        case LEFT:
            _dir = UP;
            break;
        case RIGHT:
            _dir = DOWN;
            break;
        default:
            throw std::runtime_error("Unknown direction");
        }
        return *this;
    }

    void forward(int& row, int& col) const
    {
        switch (_dir) {
        case UP:
            row--;
            break;
        case DOWN:
            row++;
            break;
        case LEFT:
            col--;
            break;
        case RIGHT:
            col++;
            break;
        default:
            throw std::runtime_error("Unknown direction");
        }
    }
};

int main(int argc, char const* argv[])
{
    bool canvas[CANVAS_HEIGHT][CANVAS_WIDTH] = { false };

    bool pen_enabled = false;

    int pos_row = 0, pos_col = 0;
    Direction dir;
    int input = 0;
    int step = -1;

    while (input != 9) {
        std::cin >> input;

        switch (input) {
        case 1:
            pen_enabled = false;
            break;
        case 2:
            pen_enabled = true;
            break;
        case 3:
            dir.turn_left();
            break;
        case 4:
            dir.turn_right();
            break;
        case 5:
            std::cin >> step;

            while (step > 0) {
                step--;
                dir.forward(pos_row, pos_col);
                canvas[pos_row][pos_col] = canvas[pos_row][pos_col] || pen_enabled;
            }
            break;
        case 6:
            for (int i = 0; i < CANVAS_HEIGHT; i++) {
                std::cout << i << "\t | ";

                for (int j = 0; j < CANVAS_WIDTH; j++) {
                    std::cout << (canvas[i][j] ? "*" : " ");
                }
                std::cout << std::endl;
            }
        case 9:
        default:
            input = 9;
            break;
        }
    }

    return 0;
}