Submission #564408

#	Time	Username	Problem	Language	Result	Execution time	Memory
564408		minhcool	Road Closures (APIO21_roads)	C++17	100 / 100	445 ms	67184 KiB

roads

#include "roads.h"
#include<bits/stdc++.h>
using namespace std;
 
#define ll long long
#define fi first
#define se second
#define pb push_back
 
typedef pair<int, int> ii;
typedef pair<ii, int> iii;
typedef pair<ii, ii> iiii;
 
const ll N = 1e5 + 5, oo = 1e18 + 7, mod = 1e9 + 7;
 
ll n;
 
set<ii> Adj[N];
 
ll k;
ll dp[N][2];

bool vis[N];

map<ii, int> mp;

int cnt[N];
vector<ll> bit1[N], bit2[N];

void upd(int u, int pos, int val){
	//cout << "UPD " << u << " " << pos << " " << val << "\n";
	int pos1 = pos, pos2 = pos;
	for(; pos1 < bit1[u].size(); pos1 += pos1 & -pos1) bit1[u][pos1]++;
	for(; pos2 < bit2[u].size(); pos2 += pos2 & -pos2) bit2[u][pos2] += val;
}

ll get(int u, int pos){
	int itr = 0;
	ll ans = 0;
	for(int i = 19; i >= 0; i--){
		if(itr + (1LL << i) >= bit1[u].size()) continue;
		if(pos >= bit1[u][itr + (1LL << i)]){
			pos -= bit1[u][itr + (1LL << i)];
			ans += bit2[u][itr + (1LL << i)];
			itr += (1LL << i);
		}
	}
	return ans;
}

 
void dfs(int u, int p, int we){
	vis[u] = 1;
	//int we = 0;
	for(auto it : Adj[u]){
		int v = it.fi;
		if(v == p){
			//we = it.se;
			continue;
		}
		//assert(Adj[v].size() > k);
		//if(Adj[v].size() <= k) continue;
		dfs(v, u, it.se);
	}
	vector<ll> vc;
	ll sum = 0;
	for(auto it : Adj[u]){
		int v = it.fi;
		if(v == p) continue;
		//cout << "EDG " << u << " " << v << "\n";
		sum += dp[v][0];
		if(dp[v][0] > dp[v][1]) vc.pb(dp[v][0] - dp[v][1]);
	}
	sort(vc.begin(), vc.end());
	reverse(vc.begin(), vc.end());
	sum += get(u, cnt[u]);
	ll sum2 = 0, opt = -oo;
	//cout << cnt[u] << "\n";
	for(int i = 0; i <= vc.size(); i++){
		if((k - 1) < i) break;
		opt = max(opt, sum2 + get(u, k - 1 - i));
		if(i == vc.size()) break;
		sum2 += vc[i];
	}
	//cout << "OK " << cnt[u] << " " << get(u, cnt[u]) << " " << sum << " " << opt << "\n";
	dp[u][1] = sum - opt;
	sum2 = 0, opt = -oo;
	//cout << vc.size() << "\n";
	for(int i = 0; i <= vc.size(); i++){
		if(k < i) break;
		opt = max(opt, sum2 + get(u, k - i));
		if(i == vc.size()) break;
		sum2 += vc[i];
	}
	dp[u][0] = sum - opt + we;
	//cout << u << " " << dp[u][0] << " " << dp[u][1] << "\n";
	/*
	for(int i = 0; i < min((ll)vc.size(), (ll)k - 1); i++){
		sum2 += max(0LL, vc[i]);
	}*/
	/*
	dp[u][0] = sum - sum2 - (((ll)vc.size() < k || !k) ? 0 : max(0LL, vc[k - 1])) + we;
	dp[u][1] = sum - sum2;*/
	//cout << u << " " << dp[u][0] << " " << dp[u][1] << "\n";
}
 
bool ck_star(){
	int tol = 0;
	for(int i = 1; i <= n; i++) tol += (Adj[i].size() >= 2);
	return (tol == 1);
}
 
bool ck_line(){
	for(int i = 1; i <= n; i++) if(Adj[i].size() > 2) return 0;
	return 1;
}
 
vector<long long> minimum_closure_costs(int N, vector<int> U, vector<int> V, vector<int> W){
	n = N;
	//cout << U.size() << " " << V.size() << " " << W.size() << "\n";
	//exit(0);
	for(int i = 0; i < (n - 1); i++){
		U[i]++, V[i]++;
		Adj[U[i]].insert({V[i], W[i]});
		Adj[V[i]].insert({U[i], W[i]});
	}
	set<ii> nodes;
	for(int i = 1; i <= n; i++) nodes.insert({Adj[i].size(), i});
	for(int i = 1; i <= n; i++){
		bit1[i].resize(Adj[i].size() + 1);
		bit2[i].resize(Adj[i].size() + 1);
		int cnt = 0;
		vector<ii> temp;
		for(auto it : Adj[i]) temp.pb({it.se, it.fi}); 
		sort(temp.begin(), temp.end(), greater<ii>());
		for(auto it : temp){
			if(it.fi <= 0) break;
			cnt++;
			mp[{i, it.se}] = cnt;
		}
	}
	/*
	if(ck_star()){
		sort(W.begin(), W.end(), greater<int>());
		vector<ll> ans(n);
		ll sum = 0;
		for(int i = n - 1; i >= 0; i--){
			ans[i] = sum;
			if(i) sum += W[i - 1];
		}
		return ans;
	}*/
	int mx_deg = 0;
	for(int i = 1; i <= n; i++) mx_deg = max(mx_deg, (int)Adj[i].size());
	vector<ll> ans;
	//cout << "OK\n";
	for(int i = 0; i < mx_deg; i++){
		k = i;
		while(nodes.size() && (*nodes.begin()).fi <= k){
			int u = (*nodes.begin()).se;
			for(auto it : Adj[u]){
				int v = it.fi, w = it.se;
				cnt[v]++;
				if(mp.find({v, u}) != mp.end()) upd(v, mp[{v, u}], w);
				//Adj[u].erase({v, w});
				Adj[v].erase({u, w});
			}
			Adj[u].clear();
			//cout << u << " " << i << "\n";
			nodes.erase(nodes.begin());
		}
		for(auto it : nodes) vis[it.se] = 0;
		ll answ = 0;
		//cout << i << "\n";
		for(auto it : nodes){
			//assert(Adj[it.se].size() > k);
			if(!vis[it.se]){
				//cout << i << " " << it.se << "\n";
				dfs(it.se, it.se, 0);
				answ += min(dp[it.se][0], dp[it.se][1]);
			}
		}
		ans.pb(answ);
		/*
		k = i;
		dfs(1, 1);
		ans.pb(min(dp[1][0], dp[1][1]));*/
	}
	for(int i = mx_deg; i < n; i++) ans.pb(0);
	return ans;
}
 
/*
void process(){
	int n;
	vector<int> a, b, c;
	cin >> n;
	for(int i = 1; i <= 3 * n - 3; i++){
		int x;
		cin >> x;
		if(i <= (n - 1)) a.pb(x);
		else if(i <= 2 * (n - 1)) b.pb(x);
		else c.pb(x);
	}
	vector<long long> temp = minimum_closure_costs(n, a, b, c);
	for(auto it : temp) cout << it << " ";
}
 
signed main(){
	ios_base::sync_with_stdio(0);
	freopen("roads.inp", "r", stdin);
	freopen("roads.out", "w", stdout);
	process();
}*/

Compilation message (stderr)

roads.cpp: In function 'void upd(int, int, int)':
roads.cpp:33:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |  for(; pos1 < bit1[u].size(); pos1 += pos1 & -pos1) bit1[u][pos1]++;
      |        ~~~~~^~~~~~~~~~~~~~~~
roads.cpp:34:13: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   34 |  for(; pos2 < bit2[u].size(); pos2 += pos2 & -pos2) bit2[u][pos2] += val;
      |        ~~~~~^~~~~~~~~~~~~~~~
roads.cpp: In function 'long long int get(int, int)':
roads.cpp:41:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   41 |   if(itr + (1LL << i) >= bit1[u].size()) continue;
      |      ~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
roads.cpp: In function 'void dfs(int, int, int)':
roads.cpp:79:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 |  for(int i = 0; i <= vc.size(); i++){
      |                 ~~^~~~~~~~~~~~
roads.cpp:82:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |   if(i == vc.size()) break;
      |      ~~^~~~~~~~~~~~
roads.cpp:89:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   89 |  for(int i = 0; i <= vc.size(); i++){
      |                 ~~^~~~~~~~~~~~
roads.cpp:92:8: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |   if(i == vc.size()) break;
      |      ~~^~~~~~~~~~~~

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