Submission #696712

#	Time	Username	Problem	Language	Result	Execution time	Memory
696712		SanguineChameleon	Parkovi (COCI22_parkovi)	C++17	0 / 110	238 ms	21604 KiB

Main

// BEGIN BOILERPLATE CODE

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

#ifdef KAMIRULEZ
	const bool kami_loc = true;
	const long long kami_seed = 69420;
#else
	const bool kami_loc = false;
	const long long kami_seed = chrono::steady_clock::now().time_since_epoch().count();
#endif

const string kami_fi = "kamirulez.inp";
const string kami_fo = "kamirulez.out";
mt19937_64 kami_gen(kami_seed);

long long rand_range(long long rmin, long long rmax) {
	uniform_int_distribution<long long> rdist(rmin, rmax);
	return rdist(kami_gen);
}

long double rand_real(long double rmin, long double rmax) {
	uniform_real_distribution<long double> rdist(rmin, rmax);
	return rdist(kami_gen);
}

void file_io(string fi, string fo) {
	if (fi != "" && (!kami_loc || fi == kami_fi)) {
		freopen(fi.c_str(), "r", stdin);
	}
	if (fo != "" && (!kami_loc || fo == kami_fo)) {
		freopen(fo.c_str(), "w", stdout);
	}
}

void set_up() {
	if (kami_loc) {
		file_io(kami_fi, kami_fo);
	}
	ios_base::sync_with_stdio(0);
	cin.tie(0);
}

void just_do_it();

void just_exec_it() {
	if (kami_loc) {
		auto pstart = chrono::steady_clock::now();
		just_do_it();
		auto pend = chrono::steady_clock::now();
		long long ptime = chrono::duration_cast<chrono::milliseconds>(pend - pstart).count();
		string bar(50, '=');
		cout << '\n' << bar << '\n';
		cout << "Time: " << ptime << " ms" << '\n';
	}
	else {
		just_do_it();
	}
}

int main() {
	set_up();
	just_exec_it();
	return 0;
}

// END BOILERPLATE CODE

// BEGIN MAIN CODE

const int ms = 2e5 + 20;
const long long inf = 1e18;
vector<pair<int, int>> adj[ms];
int deg[ms];
pair<int, int> par[ms];
long long mx[ms];
long long mi[ms];
bool f[ms];
long long res;
vector<int> cur;
vector<int> best;
int n, k;
int root;

void dfs(int u, int pr) {
	for (auto x: adj[u]) {
		int v = x.first;
		int w = x.second;
		if (v != pr) {
			par[v] = {u, w};
			dfs(v, u);
		}
	}
}

bool check(long long X) {
	deque<int> q;
	for (int i = 1; i <= n; i++) {
		f[i] = true;
		mx[i] = -inf;
		mi[i] = inf;
		deg[i] = adj[i].size();
		if (i != root && deg[i] == 1) {
			q.push_back(i);
		}
	}
	while (!q.empty()) {
		int u = q.front();
		q.pop_front();
		int v = par[u].first;
		long long w = par[u].second;
		if (mx[u] + w <= X && min(w, mi[u]) <= X) {
			f[u] = false;
			mx[v] = max(mx[v], max(0LL, mx[u]) + w);
			mi[v] = min(mi[v], mi[u] + w);
		}
		else {
			mi[v] = min(mi[v], w);
		}
		deg[v]--;
		if (v != root && deg[v] == 1) {
			q.push_back(v);
		}
	}
	if (mi[1] <= X) {
		f[1] = false;
	}
	cur.clear();
	for (int i = 1; i <= n; i++) {
		if (f[i]) {
			cur.push_back(i);
		}
	}
	return ((int)cur.size() <= k);
}

void just_do_it() {
	cin >> n >> k;
	for (int i = 0; i < n - 1; i++) {
		int u, v, w;
		cin >> u >> v >> w;
		adj[u].push_back({v, w});
		adj[v].push_back({u, w});
	}
	for (int i = 1; i <= n; i++) {
		deg[i] = adj[i].size();
		if (deg[i] > 1) {
			root = i;
			break;
		}
	}
	dfs(root, -1);
	long long lt = 0;
	long long rt = 2e14;
	while (lt <= rt) {
		long long mt = (lt + rt) / 2;
		if (check(mt)) {
			best = cur;
			res = mt;
			rt = mt - 1;
		}
		else {
			lt = mt + 1;
		}
	}
	for (int i = 1; i <= n; i++) {
		f[i] = false;
	}
	for (auto x: best) {
		f[x] = true;
	}
	for (int i = 1; i <= n; i++) {
		if (!f[i] && (int)best.size() < k) {
			best.push_back(i);
		}
	}
	cout << res << '\n';
	for (auto x: best) {
		cout << x << " ";
	}
}

// END MAIN CODE

Compilation message (stderr)

Main.cpp: In function 'void file_io(std::string, std::string)':
Main.cpp:30:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |   freopen(fi.c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:33:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   33 |   freopen(fo.c_str(), "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 30
• Subtask 4: 0 / 60