class Solution {
public:
    vector<int> advantageCount(vector<int>& A, vector<int>& B) {
        int len = A.size();
        map<int, int> bst;
        for(const auto& num : A)++bst[num];
        vector<int> res(len, 0);
        for(int i = 0; i < len; ++i)
        {
            auto iter = bst.upper_bound(B[i]);
            if(iter == bst.end())
            {
                res[i] = bst.begin()->first;
                --bst.begin()->second;
                if(bst.begin()->second == 0)
                    bst.erase(bst.begin());
            }
            else
            {
                res[i] = iter->first;
                --iter->second;
                if(iter->second == 0)
                    bst.erase(iter);
            }
        }
        return res;
    }
};