очередь

#include <iostream>
#include <cmath>

using namespace std;

class IQueue
{
   int *arr, length, first, last;
public:
   IQueue(int len);
   void push(int val);
   int pop();
};

IQueue::IQueue(int len)
{
   arr = new int [len];
   length = len;
   first = 0;
   last = -1;
}

void IQueue::push(int val)
{
   if (last < length-1)
      arr[++last] = val;
}

int IQueue::pop()
{
   if (first == last+1)
     return -1;
   return arr[first++];
}

 void sift_all (int *arr, int first, int last)

 {
  int j = first;
  int k = first*2+1;

  while (k <= last)
  {
    if (k < last && arr[k+1] < arr[k])
     k++;
     if (arr[j] < arr[k])
     break;
     else if (arr[j] >= arr[k])
     {
        swap(arr[j], arr[k]);
         j = k;
         k = k*2+1;
     }
 }
}

int main()
{
  int n, k, time_i;
  cin >> n >> k;

  IQueue train_ticket(n);

  for (int i = 0; i < n; i++)
   {
     cin >> time_i;
     train_ticket.push(time_i);
   }

  int *kassa = new int[k];

  for (int i = 0; i < k; i++)
   kassa[i] = 0;

  for (int i = 0; i < n; i++)
  {
    time_i = train_ticket.pop();
    sift_all(kassa, 0, k-1);
    kassa[0] += time_i;
  }

  int max = 0;

  for (int i = 1; i < k; i++)
   if (kassa[i] > kassa[max])
    max = i;

  cout << kassa[max];
}