Submission #991184

#	Time	Username	Problem	Language	Result	Execution time	Memory
991184		alex_2008	Beech Tree (IOI23_beechtree)	C++17	23 / 100	118 ms	22480 KiB

beechtree

#include "beechtree.h"
#include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <map>
#include <set>
using namespace std;
const int N = 2e5 + 10;
vector <vector<pair<int, int>>> G;
vector <pair<int, int>> get_subtree(int v, int c) {
	vector <pair<int, int>> cur;
	cur.push_back({ v, c });
	for (auto it : G[v]) {
		for (auto& j : get_subtree(it.first, it.second)) {
			cur.push_back(j);
		}
	}
	return cur;
}
bool check(vector <pair<int, int>>& w, vector <int>& P, vector <int>& C) {
	map <int, int> mp;
	for (int i = 1; i < (int)w.size(); i++) {
		if (P[w[i].first] != w[mp[w[i].second]].first) return false;
		mp[w[i].second]++;
	}
	return true;
}
bool cmp(set <int> x, set <int> y) {
	return (int)x.size() > (int)y.size();
}
vector <int> beechtree(int N, int M, vector <int> P, vector <int> C) {
	bool subtask1 = (N <= 8);
	bool subtask2 = true;
	bool subtask3 = true;
	bool subtask4 = true;
	G.clear();
	G.resize(N);
	map <int, int> mp;
	for (int i = 1; i < N; i++) {
		if (P[i] != (i - 1)) {
			subtask2 = false;
		}
		G[P[i]].push_back({ i, C[i] });
		mp[C[i]]++;
		if (P[i] != 0 && P[P[i]] != 0) {
			subtask3 = false;
		}
	}
	for (auto it : mp) {
		if (it.second > 2) {
			subtask4 = false;
		}
	}
	if (subtask1) {
		vector <int> ret = {};
		for (int i = 0; i < N; i++) {
			vector <pair<int, int>> w = get_subtree(i, C[i]);
			sort(w.begin() + 1, w.end());
			bool ch = false;
			if (check(w, P, C)) ch = true;
			while (next_permutation(w.begin() + 1, w.end())) {
				if (check(w, P, C)) ch = true;
			}
			ret.push_back(ch);
		}
		return ret;
	}
	if (subtask2) {
		vector <int> ret = {};
		if (N == 1) return { 1 };
		int cnt = 2;
		for (int i = N - 2; i > 0; i--) {
			if (C[i] != C[N - 1]) break;
			cnt++;
		}
		for (int i = 0; i < N - cnt; i++) {
			ret.push_back(0);
		}
		for (int i = 0; i < cnt; i++) {
			ret.push_back(1);
		}
		return ret;
	}
	if (subtask3) {
		bool esim = true;
		vector <int> ret(N, 0);
		vector <set<int>> sets;
		for (int i = N - 1; i >= 1; i--) {
			if (G[i].empty()) {
				ret[i] = 1;
			}
			else {
				bool ch = true;
				set <int> ms;
				for (auto it : G[i]) {
					if (ms.find(it.second) != ms.end()) {
						esim = false;
						ch = false;
					}
					ms.insert(it.second);
				}
				if (ch) {
					ret[i] = 1;
					sets.push_back(ms);
				}
			}
		}
		if (!esim) return ret;
		set <int> ms;
		for (auto it : G[0]) {
			if (ms.find(it.second) != ms.end()) {
				return ret;
			}
			ms.insert(it.second);
		}
		sort(sets.begin(), sets.end(), cmp);
		for (auto& it : sets) {
			for (auto& j : it) {
				if (ms.find(j) == ms.end()) {
					return ret;
				}
			}
			ms = it;
		}
		ret[0] = 1;
		return ret;
	}
	if (subtask4) {
		vector <int> ret(N, 0);
		vector <bool> lvl1(N, 0);
		vector <bool> different(N, true);
		vector <set<int>> sets(N, set<int>());
		for (int v = N - 1; v >= 0; v--) {
			if (G[v].empty()) {
				ret[v] = 1;
				continue;
			}
			lvl1[v] = true;
			for (auto &it : G[v]) {
				if (!G[it.first].empty()) lvl1[v] = false;
			}
			if (lvl1[v]) {
				for (auto &it : G[v]) {
					if (sets[v].find(it.second) != sets[v].end()) {
						different[v] = false;
					}
					sets[v].insert(it.second);
				}
				if (different[v]) {
					ret[v] = 1;
					continue;
				}
			}
			bool lvl2 = true;
			for (auto it : G[v]) {
				if (!G[it.first].empty() && !lvl1[it.first]) {
					lvl2 = false;
				}
			}
			if (!lvl2) continue;
			bool ch = true;
			for (auto it : G[v]) {
				if (!different[it.first]) ch = false;
			}
			set <int> ms;
			for (auto it : G[v]) {
				if (ms.find(it.second) != ms.end()) {
					ch = false;
				}
				ms.insert(it.second);
			}
			vector <set<int>> cur_sets;
			for (auto it : G[v]) {
				if (!G[it.first].empty()) cur_sets.push_back(sets[it.first]);
			}
			sort(cur_sets.begin(), cur_sets.end(), cmp);
			for (auto& it : cur_sets) {
				for (auto& j : it) {
					if (ms.find(j) == ms.end()) {
						ch = false;
					}
				}
				ms = it;
			}
			ret[v] = ch;
		}
	}

}
/*
int main() {
	for (auto it : beechtree(5, 2, { -1, 0, 1, 2, 3 }, { 0, 1, 2, 2, 2 })) {
		cout << it << " ";
	}
}
*/

Compilation message (stderr)

beechtree.cpp: In function 'std::vector<int> beechtree(int, int, std::vector<int>, std::vector<int>)':
beechtree.cpp:39:17: warning: control reaches end of non-void function [-Wreturn-type]
   39 |  map <int, int> mp;
      |                 ^~

• Subtask 0: 0 / 0
• Subtask 1: 9 / 9
• Subtask 2: 5 / 5
• Subtask 3: 9 / 9
• Subtask 4: 0 / 8
• Subtask 5: 0 / 14
• Subtask 6: 0 / 14
• Subtask 7: 0 / 12
• Subtask 8: 0 / 17
• Subtask 9: 0 / 12