Yes. Using map will make your solution $$$O(n \cdot log^2 n)$$$.

Putting $$$n = 10^6$$$, number of operations = $$$4 \times 10^8$$$. You can use std::unordered_mapwhich gives constant time insertion and accessing on average ($$$O(n)$$$ in worst case). Your solution with unordered_map 173282698.