0973 K Closest Points to Origin

Solved at: 230130 K Closest Points to Origin - LeetCode

Question

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).

Solution

class Solution {
    func kClosest(_ points: [[Int]], _ k: Int) -> [[Int]] {
        var coordinates = points
        coordinates.sort {
            $0[0] * $0[0] + $0[1] * $0[1] < $1[0] * $1[0] + $1[1] * $1[1]
        }
        return Array(coordinates[...(k-1)])
    }
}

Results

• Time taken: 10 m 7 s
• Runtime 861 ms, Beats 81.63%
• Memory 16.1 MB, Beats 84.69%

Complexity Analysis

• Time $O(n \log n)$
• Space $O(n)$

Other Answers Online