1011 : Fly me to the Alpha Centauri [C++]

#include <iostream>
#include <vector>
using namespace std;

int main()
{
 int testcase;
 cin >> testcase;

 vector<long long> Slot;

 long long T = 0;
 long long Two = 2;

 for (long long i = 1; T < 4294967296; i++)
 {
  T += Two *i
  Slot.push_back(T);
 }
 
 while (testcase--)
 {
  long long x, y;
  cin >> x >> y;

  long long diff = y - x;

  if (diff == 0)
   cout << 0 << endl;
  else
  {
   int i;
   for (i = 0; i < Slot.size(); i++)
   {
    if (diff <= Slot[i])
     break;
   }
   if (diff > Slot[i] - (i + 1))
    cout << (i+1) * 2 << endl;
   else
    cout << (i+1) * 2 - 1 << endl;
  }
 }
}