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 <= K <= points.length <= 10000`

`-10000 < points[i][0] < 10000`

`-10000 < points[i][1] < 10000`

A acceptable but definitely no the best solution….

In PHP:

- a ** b means power (a,b)
- <=>, the spaceship operator, used by ‘comparator’
- if left < right return -1
- if left > right return 1
- if left == right return 0

class Solution { /** * @param Integer[][] $points * @param Integer $K * @return Integer[][] */ function kClosest($points, $K) { usort($points, function ($a, $b){ return ($a[0]**2 + $a[1]**2) <=> ($b[0]**2 + $b[1]**2); }); $result = []; $i = 0; foreach($points as $p){ if($i >= $K){ break; } $result[] = $p; $i ++; } return $result; } }