题解 | 两直线交点

class Point:
    def __init__(self, x=0.0, y=0.0):
        self.x = x
        self.y = y


class Line:
    def __init__(self, point_a=None, point_b=None):
        self.point_A = point_a if point_a is not None else Point()
        self.point_B = point_b if point_b is not None else Point()

def turn_stardard(point_a, point_b):
    A = point_b.y - point_a.y
    B = point_a.x - point_b.x
    C = point_b.x * point_a.y - point_a.x * point_b.y
    return (A, B, C)

def find_meeting_point(line_A, line_B):
    # TODO: 在这里输入你的代码，求直线 line_A 与 line_B 的交点
    A1, B1, C1 = turn_stardard(line_A.point_A, line_A.point_B)
    A2, B2, C2 = turn_stardard(line_B.point_A, line_B.point_B)
    D = A1 * B2 - B1 * A2

    if D == 0:
        return Point(-1, -1)
    else:
        x = (B1 * C2 - B2 * C1) / D
        y = (A2 * C1 - A1 * C2) / D
        return Point(x,y)



def main():
    data = list(map(float, input().split()))
    data.extend(list(map(float, input().split())))
    A = Point(data[0], data[1])
    B = Point(data[2], data[3])
    C = Point(data[4], data[5])
    D = Point(data[6], data[7])
    AB = Line(A, B)
    CD = Line(C, D)
    ans = find_meeting_point(AB, CD)
    print(f"{ans.x} {ans.y}")


if __name__ == "__main__":
    main()