K Closest Points to Origin

K Closest Points to Origin - LeetCodeLeetCode

Problem

Given an array of points where points[i] = [xi, yi] represents a point on the X-Y plane and an integer k, return the k closest points to the origin (0, 0).

The distance between two points on the X-Y plane is the Euclidean distance (i.e., √(x1 - x2)2 + (y1 - y2)2).

You may return the answer in any order. The answer is guaranteed to be unique (except for the order that it is in).

Example 1:

Input: points = [[1,3],[-2,2]], k = 1
Output: [[-2,2]]
Explanation:
The distance between (1, 3) and the origin is sqrt(10).
The distance between (-2, 2) and the origin is sqrt(8).
Since sqrt(8) < sqrt(10), (-2, 2) is closer to the origin.
We only want the closest k = 1 points from the origin, so the answer is just [[-2,2]].

Example 2:

Input: points = [[3,3],[5,-1],[-2,4]], k = 2
Output: [[3,3],[-2,4]]
Explanation: The answer [[-2,4],[3,3]] would also be accepted.

Pseudocode

- calculate area, sort in ascending order, splice from 0 to kth

Solution

// https://leetcode.com/problems/k-closest-points-to-origin/
var kClosest = function (points, k) {
  function distance(point) {
    return point[0] * point[0] + point[1] * point[1];
  }

  return points
    .sort((a, b) => {
      return distance(a) - distance(b);
    })
    .slice(0, k);
};

Time and Space Complexity

Time

• What did the code do

• Total -

Space

• What did the code do

• Total -