Construct list using given q XOR queries

Given a list S that initially contains a single value 0. Below are the Q queries of the following types:

• 0 X: Insert X in the list
• 1 X: For every element A in S, replace it by A XOR X.

Print all the element in the list in increasing order after performing the given Q queries.

• Time : O(nlogn)
• Space : O(n)

c++

class Solution {
public:
    vector<int> constructList(vector<vector<int>> Q, int N) {
        vector<int> res{0};
        queue<pair<int, int>> op;
        int XOR = 0;

        for(auto& q : Q) {
            if(q[0] == 0) res.push_back(q[1]);
            else {
                op.push({res.size(), q[1]});
                XOR ^= q[1];
            }
        }

        for(int i = 0; i < res.size(); i++) {
            while(!op.empty() and op.front().first == i) {
                XOR ^= op.front().second;
                op.pop();
            }
            res[i] ^= XOR;
        }
        
        sort(begin(res), end(res));

        return res;
    }
};