Submission #1019690

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019690		aeg	Parkovi (COCI22_parkovi)	C++17	110 / 110	429 ms	54956 KiB

Main

#include <bits/stdc++.h>
constexpr int maxn =  1000010;
#define en cout << "\n";
#define int int64_t
constexpr int inf = 1e18;
using namespace std;
typedef pair<int, int> pii;
typedef vector<pii> vii;
typedef vector<int> vi;
template <typename T1, typename T2>
void minimize(T1 &a, T2 b) {
	if (a > b) {
		a = b;
	}
}
template <typename T1, typename T2>
void maximize(T1 &a, T2 b) {
	if (a < b) {
		a = b;
	}
}
const int nsqrt = 450;
const int mod = 1e9 + 7;
int n, k;
vii ke[maxn];
bool covered[maxn], used[maxn];
int cnt, mid;
int dfs(int u, int par)
{
	if (ke[u].size() == 1 and u > 1)
		return 0;
	int dist = inf, reach = -inf;
	for (auto [v, w] : ke[u])
	if (v != par)
	{
		int a = dfs(v, u);
		if (a == 0 and covered[v])
		{
			maximize(reach, 0LL);
			minimize(dist, 0LL);
			continue;
		}
		if (a < 0 and a + w <= 0)
			covered[u] = 1;
		if (a < 0 and a + w > 0)
			a = 0;
		else
			a += w;
		if (a > mid)
		{
			a = min(int(-mid + w), int(0LL));
			if (-mid + w <= 0)
				covered[u] = 1;
			covered[v] = 1;
			used[v] = 1;
			++cnt;
		}
		minimize(dist, a);
		maximize(reach, a);
	}
	if (-dist >= reach)
		return dist;
	return reach;
}
int32_t main() {
#define name "TASK"
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	cin >> n >> k;
	int LIM = 0;
	for(int i = 1; i < n; i ++)
	{
		int u, v, w;
		cin >> u >> v >> w;
		ke[u].emplace_back(v, w);
		ke[v].emplace_back(u, w);
		LIM += w;
	}
	int l = 0, r = LIM, ans = LIM;
	while (l <= r)
	{
		for(int i = 1; i <= n; i ++) covered[i] = used[i] = 0;
		cnt = 0;
		mid = (l + r) >> 1;
		if (dfs(1, 1) > 0)
			used[1] = 1, ++cnt;
		else if (!covered[1])
			used[1] = 1, ++cnt;
		if (cnt <= k)
			r = mid - 1, ans = mid;
		else
			l = mid + 1;
	}
	cout << ans;
	en;
	mid = ans;
	for(int i = 1; i <= n; i ++) covered[i] = used[i] = 0;
	cnt = 0;
	if (dfs(1, 1) > 0)
		used[1] = 1, ++cnt;
	else if (!covered[1])
		used[1] = 1, ++cnt;
	vi res;
	for(int i = 1; i <= n; i++) if (used[i]) res.emplace_back(i);
	for(int i = 1; i <= n; i++) if ((int)res.size() < k and !used[i]) res.emplace_back(i);
	for (int it : res)
	cout << it << '\n';
}

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