LeetCode 149. 直线上最多的点数
给你一个数组 points ,其中 points[i] = [xi, yi] 表示 X-Y 平面上的一个点。求最多有多少个点在同一条直线上。
示例 1:
输入:points = [[1,1],[2,2],[3,3]]
输出:3
示例 2:
输入:points = [[1,1],[3,2],[5,3],[4,1],[2,3],[1,4]]
输出:4
提示:
1 <= points.length <= 300
points[i].length == 2
-104 <= xi, yi <= 104
points 中的所有点 互不相同
恰巧AC,但题解不对,还是看大佬的解法吧
class Solution:
def maxPoints(self, points: List[List[int]]) -> int:
if len(points) == 1:
return 1
combine_mapping = {}
for i in range(2, len(points) + 1):
combine_mapping[math.comb(i, 2)] = i
mapping = defaultdict(lambda: 0)
mapping[(0,0,0)] = 1
for i in range(len(points)):
for j in range(i + 1, len(points)):
(x1, y1), (x2, y2) = points[i], points[j]
a, b, c = y2 - y1, x1 - x2, x2 * y1 - x1 * y2
d = a if a else b
a, b, c = a / d, b / d, c / d
mapping[(a, b, c)] += 1
res = (0,0,0)
for i in mapping:
if combine_mapping[mapping[res]] <= combine_mapping[mapping[i]]:
res = i
return combine_mapping[mapping[res]]