Submission #533781

#	Time	Username	Problem	Language	Result	Execution time	Memory
533781		1bin	Road Closures (APIO21_roads)	C++14	29 / 100	270 ms	58020 KiB

roads

#include <bits/stdc++.h>
#include <cassert>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
set<pair<ll, ll>> adj[NMAX];
int dg[NMAX], vis[NMAX];
ll dp[NMAX][2], S[NMAX];
vector<int> D[NMAX];
set<int> X;
multiset<ll> A[NMAX], t[NMAX];

void dfs(int now, int k) {
	vis[now] = 1;
	ll& ret = dp[now][0] = 0;

	ll c = 0;
	multiset<ll> C;
	for(auto& p : adj[now]) {
		ll nx = p.first, w = p.second;
		if(vis[nx]) continue;
		dfs(nx, k);
		ret += dp[nx][0] + w;
		ll t = dp[nx][1] - dp[nx][0] - w;
		c++;
		C.emplace(t);
	}

	while(t[now].size() && (int)A[now].size() < k - c) {
		auto it = t[now].begin();
		A[now].emplace(*it); S[now] += *it;
		t[now].erase(it);
	}
	while(A[now].size() && (int)A[now].size() > k - c) {
		auto it = --A[now].end(); S[now] -= *it;
		t[now].emplace(*it);
		A[now].erase(it);
	}
	if(c >= k) assert(A[now].size() == 0);
	else assert(A[now].size() + c == k);

	ret += S[now];
	/*cout << "now is : " << now << ' ' << ret << '\n';
	for (ll x : A[now]) cout << x << ' ';
	cout << '\n';
	for (ll x : C[now]) cout << x << ' ';
	cout << '\n';*/

	auto it = t[now].begin();
	for(int i = 0; i < c && it != t[now].end(); i++) C.emplace(*it++);

	if(!c) {
		//cout << k << ' ' << now << ' ' << ret << '\n';
		//cout << ret << '\n';
		dp[now][1] = ret - *A[now].rbegin();
		return;
	}
	it = C.begin();
	int sz = k - 1 - A[now].size();
	while(sz--) ret += min(*it++, 0LL);
	dp[now][1] = ret;
	ret += min(*it, 0LL);

	//cout << ret << '\n';
	//cout << "Now is : " << now << '\n';
	//for(ll x : C[now]) cout << x << ' ';
	//cout << '\n';
	return;
}

vector<ll> minimum_closure_costs(int N, vector<int> U, vector<int> V, vector<int> W) {
	vector<ll> ans(N, 0);
	for(int i = 0; i < N - 1; i++) {
		adj[U[i]].emplace(V[i], W[i]);
		adj[V[i]].emplace(U[i], W[i]);
		dg[U[i]]++; dg[V[i]]++;
		ans[0] += W[i];
	}
	for(int i = 0; i < N; i++) {
		D[dg[i]].emplace_back(i);
		X.emplace(i);
	}

	for(int k = 1; k < N; k++) {
		// 노드 삭제하기
		//cout << "NOW TURN IS : " << k << '\n';
		for(int x : D[k]) {
			X.erase(x);
			//cout << "erase : " << x << '\n';
			for(auto& p : adj[x]) {
				ll nx = p.first, w = p.second;
				adj[nx].erase({ x, w });
				S[nx] += w; t[nx].emplace(-w);
			}
		}

		// 각 트리에 대해서 탐색

		for(int x : X) if(!vis[x]) {
			dfs(x, k);
			ans[k] += dp[x][0];
		}
		for(int x : X) vis[x] = 0;
	}
	return ans;
}


/*
5
0 1 1
0 2 4
0 3 3
2 4 2
*/

/*
4
0 1 5
0 3 5
0 2 10
*/

/*
5
0 1 5
1 2 6
2 3 1
3 4 8
*/

/*
5
0 1 1
0 2 2
0 3 3
0 4 4
*/

//int main(void) {
//	ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//
//	freopen("input.txt", "r", stdin);
//	int N;
//	cin >> N;
//	vector<int> U(N), V(N), W(N);
//	for(int i = 0; i < N - 1; i++) cin >> U[i] >> V[i] >> W[i];
//	vector<ll> ans = minimum_closure_costs(N, U, V, W);
//	for(int i = 0; i < N; i++) cout << ans[i] << ' ';
//	return 0;
//}

Compilation message (stderr)

In file included from /usr/include/c++/10/cassert:44,
                 from roads.cpp:2:
roads.cpp: In function 'void dfs(int, int)':
roads.cpp:43:32: warning: comparison of integer expressions of different signedness: 'long long unsigned int' and 'int' [-Wsign-compare]
   43 |  else assert(A[now].size() + c == k);
      |              ~~~~~~~~~~~~~~~~~~^~~~

• Subtask 1: 5 / 5
• Subtask 2: 7 / 7
• Subtask 3: 0 / 14
• Subtask 4: 0 / 10
• Subtask 5: 17 / 17
• Subtask 6: 0 / 25
• Subtask 7: 0 / 22