[LeetCode]题解(python):149-Max Points on a Line
题目来源:
https://leetcode.com/problems/max-points-on-a-line/
题意分析:
在一个2D的板上面有很多个点,判断最多有多少个点在同一条直线上。
题目思路:
这里我们可以用斜率来记录两条边是否在同一条直线。如果考虑再细一点,由于double有精度的问题,斜率最后用分数来表示。
代码(python):
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
# Definition for a point. # class Point(object): # def __init__(self, a=0, b=0): # self.x = a # self.y = b class Solution(object): def maxPoints(self, points): """ :type points: List[Point] :rtype: int """ size = len(points) if size < 3: return size ans = 0 for i in range(size): d = {'inf':0} samePoint = 1 for j in range(size): if i == j: continue elif points[i].x == points[j].x and points[i].y != points[j].y: d['inf'] += 1 elif points[i].x != points[j].x: k = 1.0 * (points[i].y - points[j].y) / (points[i].x - points[j].x) if k in d: d[k] += 1 else: d[k] = 1 else: samePoint += 1 ans = max(ans,max(d.values()) + samePoint) return ans