Submission #697079

#	Time	Username	Problem	Language	Result	Execution time	Memory
697079		baojiaopisu	Parkovi (COCI22_parkovi)	C++17	110 / 110	1282 ms	37480 KiB

Main

#include<bits/stdc++.h>

using namespace std;

using ll = long long;
using ld = long double;
using ull = unsigned long long;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pld = pair<ld, ld>;

#define fi first
#define se second
#define left BAO
#define right ANH
#define pb push_back
#define pf push_front
#define mp make_pair
#define ins insert
#define btpc __builtin_popcount
#define btclz __builtin_clz

#define sz(x) (int)(x.size());
#define all(x) x.begin(), x.end()
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int d4x[4] = {1, 0, -1, 0}; int d4y[4] = {0, 1, 0, -1};
int d8x[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int d8y[8] = {1, 1, 0, -1, -1, -1, 0, 1};

template<class X, class Y>
    bool minimize(X &x, const Y &y) {
        if (x > y)
        {
            x = y;
            return true;
        }
        return false;
    }
template<class X, class Y>
    bool maximize(X &x, const Y &y) {
        if (x < y)
        {
            x = y;
            return true;
        }
        return false;
    }

const int MOD = 1e9 + 7; //998244353

template<class X, class Y>
	void add(X &x, const Y &y) {
		x = (x + y);
		if(x >= MOD) x -= MOD;
	}

template<class X, class Y> 
	void sub(X &x, const Y &y) {
		x = (x - y);
		if(x < 0) x += MOD;
	}

/* Author : Le Ngoc Bao Anh, 12A5, LQD High School for Gifted Student*/

const ll INF = 1e9;
const int N = 2e5 + 10;

vector<pii> g[N];
ll t[N];
bool used[N], ok[N];
int cnt = 0;

void dfs(int u, int par, ll wpar, ll lim) {
	ll r = 0, c = 0;
	t[u] = ok[u] = 0;
	for(auto [v, w] : g[u]) {
		if(v != par) {
			dfs(v, u, w, lim);
			if(t[v] - w >= 0) ok[u] = true;
			if(ok[v]) maximize(r, t[v] - w);
			else maximize(c, (-t[v]) + w);
		}
	}

	if(r >= c) t[u] = r;
	else {
		t[u] = -c;
		ok[u] = false;
	}

	if(u == 1 && !ok[u]) {
		used[u] = 1;
		++cnt;
		return;
	}

	if(!ok[u] && -(t[u] - wpar) > lim) {
		t[u] = lim;
		ok[u] = true;
		used[u] = true;
		++cnt;
	}
}

void BaoJiaoPisu() {
	int n, k; cin >> n >> k;
	for(int i = 1; i < n; i++) {
		int u, v, w; cin >> u >> v >> w;
		g[u].pb(mp(v, w));
		g[v].pb(mp(u, w));
	}

	if(k == n) {
		cout << 0 << '\n';
		for(int i = 1; i <= n; i++) cout << i << " ";
		return;
	}

	vector<int> ans;
	ll l = 1, r = INF * n, res = -1;
	while(l <= r) {
		ll mid = (l + r) >> 1;
		for(int i = 1; i <= n; i++) used[i] = false;
			
		cnt = 0;
		dfs(1, 0, 0, mid);
		
		if(cnt <= k) {
			ans.clear();
			res = mid;
			for(int i = 1; i <= n; i++) {
				if(used[i]) ans.pb(i);
			}

			for(int i = 1; i <= n; i++) {
				if(!used[i] && ans.size() < k) ans.pb(i);
			}
			r = mid - 1;
		} else l = mid + 1;
	}

	cout << res << '\n';
	for(auto x : ans) cout << x << " ";
}

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

    int tc = 1, ddd = 0;
    // cin >> tc;
    while(tc--) {
        //ddd++;
        //cout << "Case #" << ddd << ": ";
        BaoJiaoPisu();
    }
}

Compilation message (stderr)

Main.cpp: In function 'void BaoJiaoPisu()':
Main.cpp:140:31: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
  140 |     if(!used[i] && ans.size() < k) ans.pb(i);
      |                    ~~~~~~~~~~~^~~
Main.cpp: In function 'int main()':
Main.cpp:154:17: warning: unused variable 'ddd' [-Wunused-variable]
  154 |     int tc = 1, ddd = 0;
      |                 ^~~

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