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
class Solution:
    def kClosest(self, points: List[List[int]], K: int) -> List[List[int]]:
        def partition(start, end):
            pivot = start
            left = start+1
            right = end
            while True:
                while left < right and comparer(points[pivot], points[left]):
                    left += 1
                while left <= right and comparer(points[right], points[pivot]):
                    right -= 1
                if left >= right: 
                    break
                points[left], points[right] = points[right], points[left]
            points[pivot], points[right] = points[right], points[pivot]
            return right
        def comparer(point1, point2):
            return (point1[0]**2+point1[1]**2)>=(point2[0]**2+point2[1]**2)
        
        left, right, mid = 0, len(points)-1, 0
        while left<=right:
            mid = partition(left, right)
            if mid == K-1:
                break
            elif mid > K-1:
                right = mid - 1
            else:
                left = mid + 1
        return points[:K]
class Solution:
    def kClosest(self, points: List[List[int]], K: int) -> List[List[int]]:
        def partition(start, end):
            pivot = start
            left = start+1
            right = end
            while True:
                while left < right and comparer(points[pivot], points[left]):
                    left += 1
                while left <= right and comparer(points[right], points[pivot]):
                    right -= 1
                if left >= right: 
                    break
                points[left], points[right] = points[right], points[left]
            points[pivot], points[right] = points[right], points[pivot]
            return right
        def comparer(point1, point2):
            return (point1[0]**2+point1[1]**2)>=(point2[0]**2+point2[1]**2)
        
        left, right, mid = 0, len(points)-1, 0
        while left<=right:
            mid = partition(left, right)
            if mid == K-1:
                break
            elif mid > K-1:
                right = mid - 1
            else:
                left = mid + 1
        return points[:K]