Submission #1160943

#	Time	Username	Problem	Language	Result	Execution time	Memory
1160943		jmyszka2007	Pastiri (COI20_pastiri)	C++17	100 / 100	556 ms	140564 KiB

pastiri

#include <bits/stdc++.h>
#include <fstream>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/trie_policy.hpp>
using namespace __gnu_pbds;
using namespace std;
template<class A, class B>
ostream& operator<<(ostream& o, const pair<A, B>& p) {return o << '(' << p.first << ", " << p.second << ')';}
template<size_t Index = 0, typename... Types>
ostream& printTupleElements(ostream& o, const tuple<Types...>& t) {if constexpr (Index < sizeof...(Types)){if(Index > 0){o << ", ";}o << get<Index>(t);printTupleElements<Index + 1>(o, t);}return o;}
template<typename... Types>
ostream& operator<<(ostream& o, const tuple<Types...>& t){o << "(";printTupleElements(o, t);return o << ")";}
template<class T>
auto operator<<(ostream& o, const T& x) -> decltype(x.end(), o){o << '{';bool first = true;for (const auto& e : x){if (!first){o << ", ";}o << e;first = false;} return o << '}';}
struct custom_hash {static uint64_t splitmix64(uint64_t x) {x += 0x9e3779b97f4a7c15;x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;x = (x ^ (x >> 27)) * 0x94d049bb133111eb;return x ^ (x >> 31);}
size_t operator()(uint64_t x) const {static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();return splitmix64(x + FIXED_RANDOM);}};
//#define DEBUG
#ifdef DEBUG
#define fastio()
#define debug(x...) cerr << "[" #x "]: ", [](auto... $) {((cerr << $ << "; "), ...); }(x), cerr << '\n'
#else
#define fastio() ios_base::sync_with_stdio(0); cin.tie(0);
#define debug(...)
#endif
typedef long long ll;
#define pi pair<int, int>
#define pll pair<ll, ll>
#define st first
#define nd second
#define vi vector<int>
#define vll vector<ll>
#define eb emplace_back
#define all(x) (x).begin(), (x).end()
#define sz(x) (int)(x).size()
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
void solve() {
	//ifstream cin("nazwa.in");
	//ofstream cout("nazwa.out");
	int n, k;
	cin >> n >> k;
	vector<vi>g(n + 1);
	for(int i = 1; i < n; i++) {
		int a, b;
		cin >> a >> b;
		g[a].eb(b);
		g[b].eb(a);
	}
	vi dep(n + 1, 0);
	int lg = 0;
	while((1 << (lg + 1)) <= n - 1) {
		lg++;
	}
	vector<vi>nxt(n + 1, vi(lg + 1, 0));
	auto calc = [&](auto &&calc, int v, int o) -> void {
		nxt[v][0] = o;
		for(int i = 1; i <= lg; i++) {
			nxt[v][i] = nxt[nxt[v][i - 1]][i - 1];
		}
		for(auto x : g[v]) {
			if(x != o) {
				dep[x] = dep[v] + 1;
				calc(calc, x, v);
			}
		};
	};
	calc(calc, 1, 1);
	vector<pi>kt;
	for(int i = 1; i <= k; i++) {
		int x;
		cin >> x;
		kt.eb(dep[x], x);
	}
	sort(all(kt));
	reverse(all(kt));
	vi dist(n + 1, 1e9);
	queue<int>q;
	for(auto [D, v] : kt) {
		dist[v] = 0;
		q.emplace(v);
	}
	while(!q.empty()) {
		int v = q.front();
		q.pop();
		for(auto x : g[v]) {
			if(dist[x] == 1e9) {
				dist[x] = dist[v] + 1;
				q.emplace(x);
			}
		}
	}
	vector<vi>g2(n + 1);
	for(int i = 1; i <= n; i++) {
		for(auto x : g[i]) {
			if(dist[x] == dist[i] - 1) {
				g2[i].eb(x);
			}
		}
	}
	vi vis(n + 1, 0);
	auto mark = [&](auto &&mark, int v) -> void {
		vis[v] = 1;
		for(auto x : g2[v]) {
			if(!vis[x]) {
				mark(mark, x);
			}
		}
	};
	vi res;
	for(auto [D, v] : kt) {
		if(vis[v]) {
			continue;
		}
		int sum = 0;
		for(int i = lg; i >= 0; i--) {
			if(dist[nxt[v][i]] == sum + (1 << i)) {
				sum += (1 << i);
				v = nxt[v][i];
			}
		}
		res.eb(v);
		mark(mark, v);
	}
	sort(all(res));
	cout << sz(res) << '\n';
	for(auto x : res) {
		cout << x << ' ';
	}
	cout << '\n';
}
int main() {
	fastio();
	int t = 1;
	//cin >> t;
	while(t--) {
		solve();
	}
}

• Subtask 1: 8 / 8
• Subtask 2: 18 / 18
• Subtask 3: 23 / 23
• Subtask 4: 51 / 51