#include <iostream>
#include <fstream>
#include <sstream>
#include <vector>
#include <cstdint>
using namespace std;

struct Money
{
    int64_t cents;

    inline Money& operator+=(Money m)
    {
        cents += m.cents;
        return *this;
    }

    inline Money& operator-=(Money m)
    {
        cents -= m.cents;
        return *this;
    }

    inline Money& operator*=(int64_t multiplier)
    {
        cents *= multiplier;
        return *this;
    }

    inline Money& operator/=(int64_t divisor)
    {
        cents /= divisor;
        return *this;
    }
};

constexpr Money operator-(Money money)
{
    return {-money.cents};
}

constexpr Money operator+(Money a, Money b)
{
    return {a.cents + b.cents};
}

constexpr Money operator-(Money a, Money b)
{
    return {a.cents - b.cents};
}

constexpr Money operator*(Money a, int64_t b)
{
    return {a.cents * b};
}

constexpr Money operator/(Money a, int64_t b)
{
    return {a.cents / b};
}

constexpr bool operator==(Money a, Money b)
{
    return a.cents == b.cents;
}

constexpr bool operator!=(Money a, Money b)
{
    return a.cents != b.cents;
}

constexpr bool operator<(Money a, Money b)
{
    return a.cents < b.cents;
}

constexpr bool operator<=(Money a, Money b)
{
    return a.cents <= b.cents;
}

constexpr bool operator>(Money a, Money b)
{
    return a.cents > b.cents;
}

constexpr bool operator>=(Money a, Money b)
{
    return a.cents >= b.cents;
}

ostream& operator<<(ostream& stream, Money money)
{
    uint64_t cents = money.cents;

    if (money.cents < 0)
    {
        stream << '-';
        cents = -money.cents;
    }

    uint64_t dollars = cents / 100;
    cents -= dollars * 100;

    stream << dollars << '.';

    if (cents < 10) stream << '0';

    return stream << cents;
}

struct Loan
{
    Money principal;
    int64_t interest; // 1 = 0.01%
    Money minPayment;
};

void RunSimulation(vector<Loan> loans, Money monthlyIncome)
{
    static int fileId = 0;
    stringstream ss;
    ss << "loan_" << ++fileId << ".txt";

    ofstream fout(ss.str(), ofstream::binary);

    int monthCount = 0;
    Money totalPaid{0};

    Money minMonthlyIncome{0};
    for (auto loan : loans) minMonthlyIncome += loan.minPayment;

    if (monthlyIncome < minMonthlyIncome)
    {
        cout << '$' << monthlyIncome << " is not enough. Minimum income is $"
            << minMonthlyIncome << ".\n";

        monthlyIncome = minMonthlyIncome;
    }

    bool keepPaying = true;
    int n = 0;

    while (keepPaying)
    {
        auto income = monthlyIncome;
        ++monthCount;

        // Pay minimum amounts.

        fout << "Month " << monthCount << '\n';

        for (auto& loan : loans)
        {
            loan.principal -= loan.minPayment;
            income -= loan.minPayment;
            totalPaid += loan.minPayment;

            if (loan.principal.cents < 0)
            {
                income -= loan.principal;
                totalPaid += loan.principal;
                loan.principal = {0};
            }

            fout << "principal: " << loan.principal << '\n';
        }

        // Apply excess.

        for (size_t i = loans.size(); i > 0 && income.cents > 0; --i)
        {
            auto& loan = loans[i - 1];
            loan.principal -= income;
            totalPaid += income;

            if (loan.principal.cents < 0)
            {
                income -= loan.principal;
                totalPaid += loan.principal;
                loan.principal = {0};
            }
        }

        // Apply interest.

        keepPaying = false;

        for (auto& loan : loans)
        {
            auto interest = loan.principal * loan.interest / 120000;
            fout << "interest: " << interest << '\n';
            keepPaying |= loan.principal.cents > 0;
            loan.principal += interest;
        }
    }

    cout << "paid $" << totalPaid << " over " << monthCount << " months\n";
    fout.close();
}

int main(int argc, char** argv)
{
    vector<Loan> loans;
    loans.push_back({{2000000}, 800, {19113}});
    loans.push_back({{200000}, 800, {4055}});
    loans.push_back({{500000}, 1800, {12697}});
    cout << "HIL first\n";
    RunSimulation(loans, {});

    loans.clear();
    loans.push_back({{2000000}, 800, {19113}});
    loans.push_back({{500000}, 1800, {12697}});
    loans.push_back({{200000}, 800, {4055}});
    cout << "LPL first\n";
    RunSimulation(loans, {});

    return 0;
}