#include <bits/stdc++.h>
using namespace std;
#define int long long

signed main() {
	int n, a, b, c;
	a = 0, b = 0, c = 0;
	cin >> n;
	for (int i = 1; i <= 1000000; i++) {
		if()
		cout << a << " " << b << " " << c++ << endl;
		if (c > n) {
			c = 0;
			b++;
		}
		if (b > n) {
			c = 0;
			b = 0;
			a++;
		}
		if (a > n)
			break;
	}
	return 0;
}

输出:

0 0 0
0 0 1
0 0 2
0 0 3
0 1 0
0 1 1
0 1 2
0 1 3
0 2 0
0 2 1
0 2 2
0 2 3
0 3 0
0 3 1
0 3 2
0 3 3
1 0 0
1 0 1
1 0 2
1 0 3
1 1 0
1 1 1
1 1 2
1 1 3
1 2 0
1 2 1
1 2 2
1 2 3
1 3 0
1 3 1
1 3 2
1 3 3
2 0 0
2 0 1
2 0 2
2 0 3
2 1 0
2 1 1
2 1 2
2 1 3
2 2 0
2 2 1
2 2 2
2 2 3
2 3 0
2 3 1
2 3 2
2 3 3
3 0 0
3 0 1
3 0 2
3 0 3
3 1 0
3 1 1
3 1 2
3 1 3
3 2 0
3 2 1
3 2 2
3 2 3
3 3 0
3 3 1
3 3 2
3 3 3

样例：

0 0 0
0 0 1
0 0 2
0 0 3
0 1 0
0 1 1
0 1 2
0 2 0
0 2 1
0 3 0
1 0 0
1 0 1
1 0 2
1 1 0
1 1 1
1 2 0
2 0 0
2 0 1
2 1 0
3 0 0

求调！！！