406. Queue Reconstruction by Height

class Solution {
public:
    vector<pair<int, int>> reconstructQueue(vector<pair<int, int>>& people) {
        vector<pair<int, int>> res;
        sort(people.begin(), people.end(), cmp);
        for (int i = 0; i < people.size(); i++)
            res.insert(res.begin() + people[i].second, people[i]);
        return res;
    }
private:
    static bool cmp(pair<int, int> &a, pair<int, int> &b) {
        if (a.first == b.first) return a.second < b.second;
        return a.first > b.first;
    }
};