Solution.cpp

class Solution {
public:
    vector<int> getAverages(vector<int>& nums, int k) {
        int n = nums.size();
        vector<int> ans(n, -1);
        long s = 0;
        for (int i = 0; i < n; ++i) {
            s += nums[i];
            if (i >= k * 2) {
                ans[i - k] = s / (k * 2 + 1);
                s -= nums[i - k * 2];
            }
        }
        return ans;
    }
};