제출 #246333

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
246333		tonowak	Toys (CEOI18_toy)	C++14	59 / 100	5066 ms	3452 KiB

toy

#include <bits/stdc++.h> // Tomasz Nowak
using namespace std;     // XIII LO Szczecin
using LL = long long;    // Poland
#define FOR(i, l, r) for(int i = (l); i <= (r); ++i)
#define REP(i, n) FOR(i, 0, (n) - 1)
template<class T> int size(T &&x) {
	return int(x.size());
}
template<class A, class B> ostream& operator<<(ostream &out, const pair<A, B> &p) {
	return out << '(' << p.first << ", " << p.second << ')';
}
template<class T> auto operator<<(ostream &out, T &&x) -> decltype(x.begin(), out) {
	out << '{';
	for(auto it = x.begin(); it != x.end(); ++it)
		out << *it << (it == prev(x.end()) ? "" : ", ");
	return out << '}';
}
void dump() {}
template<class T, class... Args> void dump(T &&x, Args... args) {
	cerr << x << ";  ";
	dump(args...);
}
#ifdef DEBUG
  struct Nl{~Nl(){cerr << '\n';}};
# define debug(x...) cerr << (strcmp(#x, "") ? #x ":  " : ""), dump(x), Nl(), cerr << ""
#else
# define debug(...) 0 && cerr
#endif
mt19937_64 rng(0);
int rd(int l, int r) {
	return uniform_int_distribution<int>(l, r)(rng);
}
// end of templates

int n;
vector<int> curr_vec;
int curr_mul = 1;

set<int> answers;

bool can_mul(int a, int b) {
	return a <= n / b and a * b <= n;
}

void backtrack() {
	debug(curr_mul, curr_vec);
	if(curr_mul == n) {
		answers.emplace(accumulate(curr_vec.begin(), curr_vec.end(), 0));
		return;
	}
	// add new
	if(can_mul(curr_mul, 2)) {
		curr_mul *= 2;
		curr_vec.emplace_back(1);
		backtrack();
		curr_mul /= 2;
		curr_vec.pop_back();
	}

	// increase last number
	if(size(curr_vec) == 1 or (size(curr_vec) >= 2 and curr_vec.back() + 1 <= curr_vec.end()[-2])) 
		if(can_mul(curr_mul / (curr_vec.back() + 1), curr_vec.back() + 2)) {
			curr_mul /= curr_vec.back() + 1;
			++curr_vec.back();
			curr_mul *= curr_vec.back() + 1;
			backtrack();
			curr_mul /= curr_vec.back() + 1;
			--curr_vec.back();
			curr_mul *= curr_vec.back() + 1;
		}
}

int main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	cin >> n;
	backtrack();
	cout << size(answers) << '\n';
	for(int a : answers)
		cout << a << ' ';
	cout << '\n';
}

• Subtask 1: 19 / 19
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 0 / 20
• Subtask 5: 0 / 21