Question

class Solution {
public:
    vector<vector<int>> kClosest(vector<vector<int>>& points, int K) {
        vector<vector<int>> result;
        map<double, vector<int>, greater<int>> rMap;
        for (int i = 0; i < points.size(); i++) {
            int num = ((points[i][0])*(points[i][0])) + ((points[i][1])*(points[i][1]));
            double temp = sqrt(num);
            if (rMap.size() < K) {
                rMap.insert(pair<double, vector<int>>(temp, points[i]));
            }
            else {
                map<double, vector<int>>::iterator it = rMap.begin();
                if (it->first > temp) {
// rMap size seems to be fine
                    rMap.erase(rMap.find(it->first));
//rMap size still seems to be fine
                    rMap.insert(pair<double, vector<int>>(temp, points[i]));
// rMap size is the same as before the insert
// new pair is also not inserted
                }
            }
        }
        for (map<double, vector<int>>::iterator it = rMap.begin(); it != rMap.end(); it++) {
            result.push_back(it->second);
        }        
        return result;
    }
};

我做了一些内联评论。为什么map :: insert不在此处将元素添加到地图？我不是在寻找替代解决方案。我只想知道该行为的原因。

这不起作用：

您的输入：[[3,3]，[5，-1]，[-2,4]] 2

输出：[[3,3]]

预期：[[3,3]，[-2,4]]

但这可行：您的输入：[[68,97]，[34，-84]，[60,100]，[2,31]，[-27，-38]，[-73，-74]，[-55，-39] ，[62,91]，[62,92]，[-57，-67]] 5

输出：[[34，-84]，[-57，-67]，[-55，-39]，[-27，-38]，[2,31]]

预期：[[2,31]，[-27，-38]，[-55，-39]，[-57，-67]，[34，-84]]

关于使用std :: map的k个最接近原点的问题

0 个答案: