LeetCode 973 K Closest Points to Origin [sort] java

Source URL: https://leetcode.com/problems/k-closest-points-to-origin/

We have a list of points on the plane.  Find the K closest points to the origin (0, 0).

(Here, the distance between two points on a plane is the Euclidean distance.)

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]]
(The answer [[-2,4],[3,3]] would also be accepted.)

Note:

  1. 1 <= K <= points.length <= 10000
  2. -10000 < points[i][0] < 10000
  3. -10000 < points[i][1] < 10000

I make a class distance, include the distance d and the index. First, we calculate all distances, put them into a distance array. Then we sort the array by distance.

Running time is 36 ms faster than 46.32% Java submissions.

Github address: https://github.com/tinyfool/leetcode/tree/master/src/p0973

To find other sort problems, see also Sort algorithms and problems.

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