First negative integer in every window of size k

//{ Driver Code Starts
#include <bits/stdc++.h>
using namespace std;

vector<long long> printFirstNegativeInteger(long long int arr[],
                                             long long int n, long long int k);

// Driver program to test above functions
int main() {
    long long int t, i;
    cin >> t;
    while (t--) {
        long long int n;
        cin >> n;
        long long int arr[n];
        for (i = 0; i < n; i++) {
            cin >> arr[i];
        }
        long long int k;
        cin >> k;

        vector<long long> ans = printFirstNegativeInteger(arr, n, k);
        for (auto it : ans) cout << it << " ";
        cout << endl;
    }
    return 0;
}

// } Driver Code Ends


vector<long long> printFirstNegativeInteger(long long int A[],
                                             long long int N, long long int K) {

        vector<long long> ans;
        deque<long long int> dq;

        for(int i=0;i<K;i++)
        {
           if(A[i]<0)
           {
               dq.push_back(i);
           }
        }
        if(dq.size()>0)
        {
            ans.push_back(A[dq.front()]);
        }
        else
        {
            ans.push_back(0);
        }

        for(int i=K;i<N;i++)
        {
            if(!dq.empty() && i-dq.front() >=K )
            {
                dq.pop_front();
            }

            if(A[i]<0)
            {
                dq.push_back(i);
            }
             if(dq.size()>0)
            {
                ans.push_back(A[dq.front()]);
            }
            else
            {
                ans.push_back(0);
            }

        }
        return ans;

 }