973. K Closest Points to Origin

解題思路

暴力解。先 sort 一輪，拿走前 k 個就好。

程式碼

bool cmp(vector<int> p1, vector<int> p2)
{
    return sqrt(p1[0] * p1[0] + p1[1] * p1[1]) < sqrt(p2[0] * p2[0] + p2[1] * p2[1]);
}
class Solution {
public:
    vector<vector<int>> kClosest(vector<vector<int>>& points, int k) {
        sort(points.begin(), points.end(), cmp);
        vector<vector<int>> ans; 
        for(int i=0; i<k; i++)
            ans.push_back(points[i]);
        return ans;
    }
};