제출 #725754

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
725754		pavement	Cat in a tree (BOI17_catinatree)	C++17	11 / 100	4 ms	5204 KiB

catinatree

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;
#define int long long
#define mp make_pair
#define mt make_tuple
#define pb push_back
#define ppb pop_back
#define eb emplace_back
#define g0(a) get<0>(a)
#define g1(a) get<1>(a)
#define g2(a) get<2>(a)
#define g3(a) get<3>(a)
#define g4(a) get<4>(a)
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
using db = double;
using ll = long long;
using ld = long double;
using ii = pair<int, int>;
using iii = tuple<int, int, int>;
using iiii = tuple<int, int, int, int>;
using iiiii = tuple<int, int, int, int, int>;
template<class key, class value = null_type, class cmp = less<key> >
using ordered_set = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;

int N, D;
vector<int> adj[200005];

ii dp(int n) {
	bool bad = 0;
	ii tot = mp(0, 0);
	vector<ii> vec;
	for (auto u : adj[n]) {
		auto cur = dp(u);
		cur.first++;
		if (cur.first < D) bad = 1;
		tot.second += cur.second;
		vec.pb(cur);
	}
	if (!bad) {
		tot.second++;
		return tot;
	} else {
		sort(vec.begin(), vec.end());
		tot = vec.back();
		for (int i = (int)vec.size() - 1, sum = 0; i >= 1; i--) {
			sum += vec[i].second;
			if (vec[i].first + vec[i - 1].first >= D) {
				auto cand = mp(vec[i - 1].first, sum + vec[i - 1].second);
				if (cand.second > tot.second) tot = cand;
				else if (cand.second == tot.second) tot = max(tot, cand);
			}
		}
		return tot;
	}
}

main() {
	ios::sync_with_stdio(0);
	cin.tie(0);
	cin >> N >> D;
	for (int i = 1, p; i < N; i++) {
		cin >> p;
		adj[p].pb(i);
	}
	cout << dp(0).second << '\n';
}

컴파일 시 표준 에러 (stderr) 메시지

catinatree.cpp:60:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   60 | main() {
      | ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 0 / 40
• Subtask 3: 0 / 49