교점에 별 만들기

https://programmers.co.kr/learn/courses/30/lessons/87377

코딩테스트 연습 - 10주차

from itertools import combinations


def solution(lines):
    cross_points = set()
    x_max = y_max = -float('inf')
    x_min = y_min = float('inf')
    for line1, line2 in combinations(lines, 2):
        a, b, e = line1
        c, d, f = line2
        denominator = a * d - b * c
        if denominator == 0:
            continue
        cross_point_x = (b * f - e * d) / denominator
        cross_point_y = (e * c - a * f) / denominator
        if (temp_x := int(cross_point_x)) == cross_point_x and \
                (temp_y := int(cross_point_y)) == cross_point_y:
            cross_points.add((temp_x, temp_y))
            x_min, y_min = min(x_min, temp_x), min(y_min, temp_y)
            x_max, y_max = max(x_max, temp_x), max(y_max, temp_y)
    result = []
    for y in range(y_max, y_min - 1, -1):
        temp_line = []
        for x in range(x_min, x_max + 1):
            if (x, y) in cross_points:
                temp_line.append('*')
            else:
                temp_line.append('.')
        result.append(''.join(temp_line))
    return result

from itertools import combinations

def solution(lines):
    cross_points = {(x, y) for (a, b, e), (c, d, f) in combinations(lines, 2) if (denominator := a * d - b * c) != 0 and (x := int(cross_point_x := (b * f - e * d) / denominator)) == cross_point_x and (y := int(cross_point_y := (e * c - a * f) / denominator)) == cross_point_y}
    return [''.join(['*' if (x, y) in cross_points else '.' for x in range(min(cross_points, key=lambda x: x[0])[0], max(cross_points, key=lambda x: x[0])[0] + 1)]) for y in range(max(cross_points, key=lambda x: x[1])[1], min(cross_points, key=lambda x: x[1])[1] - 1, -1)]