Check If It Is a Straight Line

EasyMathmath

Solve this the way you would in the interview: out loud, on a timer, with an AI interviewer asking follow-ups while you code. You get a scored report at the end.

Practice this as a mock interviewFree to start, no account needed

Problem

You are given coordinates, a list of distinct points where coordinates[i] = [x, y] is a point on the 2D plane. Return true if every point lies on one single straight line, and false otherwise. Two points always form a line. Vertical and horizontal lines count. Aim for O(n) time and avoid floating-point division.

Examples

Input: coordinates = [[0,1],[2,5],[-1,-1],[4,9]]
Output: true
All four points satisfy y = 2x + 1.
Input: coordinates = [[1,1],[2,2],[3,4]]
Output: false
The first two points lie on y = x, but (3,4) does not.

Constraints

  • 2 <= coordinates.length <= 1000
  • coordinates[i].length == 2
  • -10^4 <= coordinates[i][0], coordinates[i][1] <= 10^4
  • All points are distinct.

What the interviewer grades

A correct solution is one of five scores. The report also grades problem understanding (did you clarify inputs and edge cases before coding), problem solving, communication while you work, code quality, and testing. See a sample report, or read up on the pattern in the lessons.

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