973. 最接近原点的 K 个点

代码思路：横纵坐标的平方和，放到新list中，然后将新list升序排，取前K个即可。

class Solution(object):
    def kClosest(self, points, K):
        """
        :type points: List[List[int]]
        :type K: int
        :rtype: List[List[int]]
        """

        mydict = {}
        for item in points:
            temp = pow(item[0], 2) + pow(item[1], 2)
            if temp in mydict.keys():
                mydict[temp].append(item)
            else:
                mydict[temp] = [item]
        mylist = sorted(mydict.items(), key=lambda x: x[0])
        res = []
        num = 0
        for item in mylist:
            res += item[1]
            num += len(item[1])
            if num >= K:
                break
        return res[:K]

代码二

class Solution(object):
    def kClosest(self, points, K):
        """
        :type points: List[List[int]]
        :type K: int
        :rtype: List[List[int]]
        """
        points.sort(key=lambda x: (x[0] ** 2 + x[1] ** 2))
        return points[:K]