先模拟，再反推

题目传送门

AC code：

#include <bits/stdc++.h>
using namespace std;
int x, a, b, c;

int main() {
	cin >> x;

	a = b = c = x / 3;

	b /= 2;
	a /= 2;
	c += (b + a);

	a /= 2;
	c /= 2;
	b += (a + c);

	b /= 2;
	c /= 2;
	a += (b + c);

	cout << a << " " << b << " " << c;



	return 0;
}