//OPT: -lpthread
#include<thread>
#include<sstream>
#include<iostream>
#include<vector>
#include<chrono>

using namespace std;
using namespace std::chrono;

class bankaccount {
public:
	bankaccount() { bal = 0; }

	void deposit(int amt) {
		m.lock();
		int currbal = bal;
		this_thread::sleep_for(milliseconds(1));
		bal = currbal + amt;
		m.unlock();
	}

	void withdraw(int amt) {
		m.lock();
		int currbal = bal;
		this_thread::sleep_for(milliseconds(1));
		bal = currbal - amt;
		m.unlock();
	}

	int balance() { return bal; }

private:
	mutex m;
	int bal; // in cents
};

void earner(bankaccount &a) {
	a.deposit(1000); // add ten dollars
	a.deposit(1000); // add ten dollars
	a.deposit(1000); // add ten dollars
}

void spender(bankaccount &a) {
	a.withdraw(800); // spend eight dollars
	a.withdraw(800); // spend eight dollars
	a.withdraw(800); // spend eight dollars
}

int main(int argc, char **argv) {
	bankaccount acct;
	thread t1(earner,ref(acct));
	thread t2(spender,ref(acct));
	t1.join();
	t2.join();
	cout << "balance = " << acct.balance() << endl;
}