#!/usr/bin/env python3
from pathlib import Path


def part_1(input):
    """The max height is reached by using the maximum start y velocity that doesn't overshoot the
    landing area. The x velocity doesn't mater here, because x position won't change after x
    velocity reaches 0. So there will always be an vx that drops straight between the x boundaries.
    Because the y velocity decreases linear we will reach our starting height after the velocity
    changed exactly to the negative value of our starting velocity. At this point we have to make
    sure not to overhoot the landing area, so the next velocity needs to be the same value as the
    lowest coordinate of the landing area to be able to start with the highest possible starting
    velocity. This leaves us with a starting velocity of abs(y_min + 1) to reach the maximum
    possible height. For positive landing coordinates y_max has to be used.
    """
    result = 0
    _, y = input[0].rstrip().replace('target area: ', '').replace(
        'x=', '').replace('y=', '').split(', ')
    y_min, _ = [int(c) for c in y.split('..')]
    vy0 = abs(y_min + 1)
    result = vy0 * (vy0 + 1) // 2
    print("Part 1 result:", result)


def part_2(input):
    result = 0
    x, y = input[0].rstrip().replace('target area: ', '').replace(
        'x=', '').replace('y=', '').split(', ')
    x_min, x_max = [int(c) for c in x.split('..')]
    y_min, y_max = [int(c) for c in y.split('..')]
    for vx_0 in range(x_max):
        for vy_0 in range(y_min, -y_min):
            vx = vx_0
            vy = vy_0
            x_pos = 0
            y_pos = 0
            while x_pos < x_max and y_pos > y_min:
                x_pos += vx
                y_pos += vy
                if vx != 0:
                    vx -= 1
                vy -= 1
                if x_min <= x_pos <= x_max and \
                        y_min <= y_pos <= y_max:
                    result += 1
                    break
    print("Part 2 result:", result)


input = list()
p = Path(__file__).with_name('input.txt')
with open(p) as f:
    input = f.readlines()
    part_1(input)
    part_2(input)