Search⌘ K
AI Features

Solution: Check If It Is a Straight Line

Understand how to check if given 2D points lie on a single straight line using the slope concept. Learn to calculate slopes between points, apply cross multiplication to compare slopes, and handle vertical lines without division errors. This lesson teaches an efficient O(n) time and O(1) space approach to solving the problem using math and geometry concepts.

Statement

You are given an array, coordinates, where each element in coordinates[i] =[x,y]= [x, y] represents the coordinates of a point on a 2D\text{2D} plane. Determine whether all the points in the array lie on a single straight line in the XY plane.

Constraints:

  • 22 \leq coordinates.length 1000\leq 1000

  • coordinates[i].length ==2== 2

  • 104-10^4 \leq coordinates[i][0]coordinates[i][1] 104\leq 10^4

  • coordinates do not contain any duplicate points.

Solution

We need to determine whether a given array of coordinates in a 2D\text{2D} plane lies in a single straight line. This problem is approached using the Math and Geometry pattern, using the slope of a straight line.

Key intuition:

The slope represents the change in y-coordinates\text{y-coordinates} relative to the change in x-coordinates\text{x-coordinates} for any two points on the line. So, the slope between two points,  ...