круговой массив

#include <iostream>
#include <cmath>

using namespace std;

int vvod (int x)
{
  cout.flush();
  int y;
  cout << "?" << " " << x << endl;
  cin >> y;
  return y;
}
int bin (int znach, int left, int right)
{
 int i = 0;
 int index_elem = -1;
 int middle;

while (left < right)
{
  i = (left + right) / 2;
 middle = vvod (i);

    if (middle < znach)
    left = i+1;
    else right = i;

}

 middle = vvod (right);

  if (middle == znach)
  index_elem = right;

return index_elem;
}

int poisk (int raznica, int left, int right)
{
 int index = 0;
 int i=(right + left)/2;
 int middle = 0;

middle = vvod (i);

  int tek_raznica = middle - i;

  if (tek_raznica < raznica)
    {
      right = i;
      if (right - left == 1)
       index = left;
      else
       return poisk (raznica, left, right);
    }
  if (tek_raznica >= raznica)
    {
      left = i;
      if (right - left == 1)
        index = left;
      else
        return poisk (raznica, left, right);
      }
 return index;
}

int main()
{
  cout.flush();
  int n = 0, m = 0, first_elem, last_elem, middle, past_middle, index, znach, k;
  cin >> n >> m;
  cin >> znach;

  first_elem = vvod(1);
  last_elem = vvod (n);

  if (last_elem > first_elem)
  index = n;
  else
  {
    int raznica = first_elem - 1;
    index = poisk (raznica, 1, n);
    middle = vvod (index);
  }

  if (znach > middle)
    k = -1;
  else if (znach == first_elem)
    k = 1;
  else if (znach == last_elem)
    k = n;
  else if (index != n && znach < last_elem)
    k = bin (znach, index+1, n);
  else if (znach > first_elem)
    k = bin (znach, 1, index);
  else if (index == n && znach < last_elem && znach > first_elem)
    k = bin (znach, 1, n);


   cout << "!" << " " << k << endl;

   for (int i = 1; i< m; i++)
   {
     int znachenie;
     cin >> znachenie;

     if (znachenie > middle)
      k = -1;
    else if (znachenie == first_elem)
      k = 1;
    else if (znachenie == last_elem)
      k = n;
    else if (index != n && znachenie < last_elem)
      k = bin (znachenie, index+1, n);
    else if (znachenie > first_elem)
      k = bin (znachenie, 1, index);
    else if (index == n && znach < last_elem && znach > first_elem)
      k = bin (znachenie, 1, n);

    cout << "!" << " " << k << endl;
   }
}