06. Truck Tour

#include <iostream>
#include <climits>
#include <queue>
#include <string>
#include <vector>
#include <sstream>
using namespace std;

bool canFinishTour(queue<int> amounts,queue<int> distances)
{
  int reservoir = 0;
  while(amounts.size())
    {
      reservoir += amounts.front();

      int distanceToNext = distances.front();
      if(reservoir >= distanceToNext)
      {
        reservoir -= distanceToNext;
      }else{
        return false;
      }

      distances.pop();
      amounts.pop();
    }
  return true;
}

int main()
{
  queue<int> distances;
  queue<int> amounts;

  int numberOfStation;

  cin >> numberOfStation;

  for(int i = 0; i < numberOfStation; i++)
    {
      int buf;
      cin >> buf;
      amounts.push(buf);
      cin >> buf;
      distances.push(buf);
    }
  int curStationStart;
  for(curStationStart = 0; curStationStart < numberOfStation; curStationStart++)
    {
      if(canFinishTour(amounts, distances))
        break;

      int distance = distances.front();
      int amount = amounts.front();
      distances.pop(); amounts.pop();
      distances.push(distance);
      amounts.push(amount);
    }
     cout << curStationStart << endl;
  return 0;
}