Day_8.Check If It Is a Straight Line

PROBLEM STATEMENT
ou 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
 

Constraints:

2 <= coordinates.length <= 1000
coordinates[i].length == 2
-10^4 <= coordinates[i][0], coordinates[i][1] <= 10^4
coordinates contains no duplicate point.

Soln:
def checkStraightLine(self, coordinates: List[List[int]]) -> bool:
        if len(coordinates)==2:
            return True
        slope=[]
        for i in range(1,len(coordinates)):
            dy=coordinates[i-1][1]-coordinates[i][1]
            dx=coordinates[i-1][0]-coordinates[i][0]
            if dx!=0:
                slope.append(dy/dx)
            else:
                slope.append('inf')
        if len(set(slope))==1:
            return True
        else:
            return False