06. Truck Tour

#include <iostream>
#include <string>
#include <queue>

using namespace std;

int main() {
    int pumps, fuel, distance;
    cin >> pumps;
    cin.ignore();

    queue<int> fuelTankPumps;

    string pump;

    for (int i = 0; i < pumps; i++) {
        getline(cin, pump);
        fuel = stoi(pump.substr(0, pump.find(' ')));
        distance = stoi(pump.substr(pump.find(' ') + 1));
        fuelTankPumps.push(fuel - distance);
    }

    int fuelQuantity = 0, index = 0;

    for (int i = 0; i < pumps; i++) {
        fuelQuantity += fuelTankPumps.front();
        fuelTankPumps.push(fuelTankPumps.front());
        fuelTankPumps.pop();

        if (fuelQuantity < 0) {
            fuelQuantity = 0;
            index = i + 1;
        }
    }

    cout << index << endl;
    return 0;
}