#149 - Max Points on a Line

Hard • View on LeetCode • View on GitHub

Problem Description

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane, return the maximum number of points that lie on the same straight line.

Solution

/**
 * @param {number[][]} points
 * @return {number}
 */
var maxPoints = function(points) {
  let max = 0;

  points.forEach(x => {
    const slopes = new Map();

    points.forEach(y => {
      if (x === y) return;
      const slope = y[0] - x[0] !== 0 ? (y[1] - x[1]) / (y[0] - x[0]) : Infinity;
      slopes.set(slope, (slopes.get(slope) || 0) + 1);
      max = Math.max(max, slopes.get(slope));
    });
  });

  return max + 1;
};