1561.cpp

class Solution {
  public:
    int maxCoins(vector<int> &piles) {
        sort(piles.begin(), piles.end());

        int res = 0;
        for (int i = piles.size() / 3; i < piles.size(); i += 2) {
            res += piles[i];
        }

        return res;
    }
};