[LeetCode]447. Number of Boomerangs

题目描述

思路

穷举解法
学map和unordered_map
后者新增时，默认初始化为0

代码

class Solution {public:    int numberOfBoomerangs(vector<pair<int, int>>& points) {        int count = 0;        for(int i = 0; i < points.size(); i++){            unordered_map<int, int> distMap;            for(int j = 0; j < points.size(); j++){                int distX = points[i].first - points[j].first;                int distY = points[i].second - points[j].second;                int dist = distX * distX + distY * distY;                count += (distMap[dist]++) * 2;            }        }        return count;    }};