LeetCode:1037有效的回旋镖(巧用内积求解三角形面积)

class Solution:
    def isBoomerang(self, points: List[List[int]]) -> bool:
        x1=points[0][0]
        x2=points[1][0]
        x3=points[2][0]

        y1=points[0][1]
        y2=points[1][1]
        y3=points[2][1]
        return (x1*(y2-y3)+x2*(y3-y1)+x3*(y1-y2))!=0