Submission #570410

#	Time	Username	Problem	Language	Result	Execution time	Memory
570410		grt	Road Closures (APIO21_roads)	C++17	0 / 100	258 ms	34088 KiB

roads

#include <bits/stdc++.h>
#define PB push_back
#define ST first
#define ND second

//#pragma GCC optimize ("O3")
//#pragma GCC target("tune=native")

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
//using namespace __gnu_pbds;
//typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;

using namespace std;
using ll = long long;
using pi = pair<int, int>;
using vi = vector<int>;

const int nax = 100 * 1000 + 10;
int n, k;
set<pi>G[nax];
ll dp[nax][2];
vi ord[nax];
bool vis[nax];
int cnt[nax];

void dfs(int x) {
	ll sum = 0;
	vis[x] = true;
	vector<ll>dx = {};
	for(auto [nbh, w] : G[x]) if(!vis[nbh]) {
		dfs(nbh);
		sum += dp[nbh][0];
		if(-dp[nbh][0] + dp[nbh][1] + w > 0) dx.PB(-dp[nbh][0] + dp[nbh][1] + w);
	}
	sum -= cnt[x];
	sort(dx.rbegin(), dx.rend());
	dp[x][0] = dp[x][1] = sum;
	for(int i = 0; i < min(k - 1, (int)dx.size()); ++i) {
		dp[x][1] += dx[i];
		dp[x][0] += dx[i];
	}
	dp[x][1] += min(cnt[x], (k - 1) - (int)dx.size());
	dp[x][0] += min(cnt[x], (k - 1) - (int)dx.size());
	if((int)dx.size() >= k) {
		dp[x][0] += dx[k - 1];
	} else if(cnt[x] > (k - 1) - (int)dx.size()) {
		dp[x][0] += 1;
	}
}


vector<ll> minimum_closure_costs(int N, vi U, vi V, vi W) {
	n = N;
	ll sum = 0;
	for(int i = 0; i < n - 1; ++i) {
		G[U[i]].insert({V[i], W[i]});
		G[V[i]].insert({U[i], W[i]});
		sum += W[i];
	}
	set<int>act = {};
	for(int i = 0; i < n; ++i) {
		act.insert(i);
	}
	for(int i = 0; i < n; ++i) {
		ord[(int)G[i].size()].PB(i);
	}
	vector<ll>res(n);
	res[0] = sum;
	ll delta = 0;
	for(k = 1; k < n; ++k) {
		for(auto v : ord[k]) {
			act.erase(v);
			for(auto [nbh, w] : G[v]) {
				if(act.count(nbh)) {
					delta += w;
					G[nbh].erase({v, w});
					cnt[nbh]++;
				}
			}	
		}
		ll s = 0;
		for(auto v : act) {
			if(!vis[v]) {
				dfs(v);
				s += dp[v][0];
			}
		}
		for(auto v : act)
			vis[v] = false;
		res[k] = (sum - (s + delta));
	}
	return res;
}


//int main() {
	//ios_base::sync_with_stdio(0);
	//cin.tie(0);
	//auto vec = minimum_closure_costs(4, {0, 2, 0}, {1, 0, 3}, {5, 10, 5});
	//auto vec1 = minimum_closure_costs(5, {0, 0, 0, 2}, {1, 2, 3, 4}, {1, 4, 3, 2});
	//cin >> n;
	//vi u(n-1), v(n-1), w(n-1);
	//for(int i = 0; i < n-1; ++i) cin >> u[i] >> v[i] >> w[i];
	//auto vec = minimum_closure_costs(n, u, v, w);
	//for(auto x : vec) cout << x << " ";
//}

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