1232.check-if-it-is-a-straight-line.py

from lc import *

# https://leetcode.com/problems/check-if-it-is-a-straight-line

class Solution:
    def checkStraightLine(self, p: List[List[int]]) -> bool:
        np=__import__('numpy');v=np.sort(np.linalg.eigvals(np.cov(p,rowvar=0)))[::-1];return np.allclose(v[1:],0)

class Solution:
    def checkStraightLine(self, p: List[List[int]]) -> bool:
        np=__import__('numpy');return all(np.cross(np.subtract(p[0],x),np.subtract(p[0],p[1]))==0 for x in p[2:])

class Solution:
    def checkStraightLine(self, p):
        return 3>__import__('numpy').linalg.matrix_rank([[1]+x for x in p])

class Solution(object):
    def checkStraightLine(self, p: List[List[int]]) -> bool:
        return all((p[1][1]-p[0][1])*(x-p[0][0])==(y-p[0][1])*(p[1][0]-p[0][0]) for x, y in p[2:])

class Solution:
    def checkStraightLine(self, p: List[List[int]]) -> bool:
        (x1,y1),(x2,y2)=p[:2];return all((x-x1)*(y2-y1)==(x2-x1)*(y-y1)for x,y in p[2:])

class Solution:
    def checkStraightLine(self, p: List[List[int]]) -> bool:
        (a,b),(c,d)=p[:2];return all((x-a)*(d-b)==(c-a)*(y-b)for x,y in p[2:])

class Solution:
    def checkStraightLine(self, p):
        (a,b),(c,d)=p[:2];return all((x-a)*(d-b)==(c-a)*(y-b)for x,y in p)

class Solution:
    def checkStraightLine(self, p):
        (a,b),(c,d),*_=p;return all((x-a)*(d-b)==(c-a)*(y-b)for x,y in p)

test('''
1232. Check If It Is a Straight Line
Easy

1345

183

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You are given an array coordinates, coordinates[i] = [x, y], where [x, y] represents the coordinate of a point. Check if these points make a straight line in the XY plane.

 

 

Example 1:



Input: coordinates = [[1,2],[2,3],[3,4],[4,5],[5,6],[6,7]]
Output: true
Example 2:



Input: coordinates = [[1,1],[2,2],[3,4],[4,5],[5,6],[7,7]]
Output: false
 

Input: coordinates = [[0,0],[0,1],[0,-1]]
Output: true

Constraints:

2 <= coordinates.length <= 1000
coordinates[i].length == 2
-10^4 <= coordinates[i][0], coordinates[i][1] <= 10^4
coordinates contains no duplicate point.
Accepted
151,912
Submissions
378,460
Seen this question in a real interview before?

Yes

No
If there're only 2 points, return true.
Check if all other points lie on the line defined by the first 2 points.
Use cross product to check collinearity.
''')