import matplotlib.pyplot as plt
from math import sin, cos, pi, sqrt

x_list = []
y_list = []


def get_koch(angle, length, gen):
    if gen > 0:
        get_koch(angle, length / 3, gen - 1)
        get_koch(angle + pi / 3, length / 3, gen - 1)
        get_koch(angle - pi / 3, length / 3, gen - 1)
        get_koch(angle, length / 3, gen - 1)
    else:
        x = x_list[-1] + length * cos(angle)
        y = y_list[-1] + length * sin(angle)

        x_list.append(x)
        y_list.append(y)


def draw_koch(angle, length, gen):
    x_list.append(-length / 2)
    y_list.append(0.25 * sqrt(1.25 * length ** 2))

    get_koch(angle, length, gen)
    get_koch(angle - 2 * pi / 3, length, gen)
    get_koch(angle + 2 * pi / 3, length, gen)

    plt.plot(x_list, y_list)
    plt.axis([-length / 1.5, length / 1.5, -length / 1.5, length / 1.5])
    plt.show()


draw_koch(0.0, 300.0, 7)