查找表_leetcode447

# 解题思路：字典先存距离信息 20190302 找工作期间
#  n2

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

        def dis( point1, point2):
            return (point1[0] - point2[0]) ** 2 + (point1[1] - point2[1]) ** 2

        result = 0
        for i in points:
            record = {}
            for j in points:
                if j != i:
                    distance = dis(i, j)
                    record[distance] = record.get(distance, 0) + 1

            for val in record.values():
                if val >= 2:
                    result += (val - 1)* val
        return result