Submission #250855

#	Time	Username	Problem	Language	Result	Execution time	Memory
250855		dvdg6566	Transport (COCI19_transport)	C++14	130 / 130	279 ms	19696 KiB

Main

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vi;
typedef pair<ll,ll> pi;
typedef vector<pi> vpi;
typedef double ld;
#define pb emplace_back
#define mp make_pair
#define lb lower_bound
#define ub upper_bound
#define ALL(x) x.begin(), x.end() 
#define SZ(x) (ll)x.size()
#define f first
#define s second
const ll MAXN=100100;
const ll MAXK=1000001;
const ll INF = 1e13;
const ll MOD = 1e9+7;

ll A[MAXN];
vi tmin,tmout;

ll res(){
	sort(ALL(tmin));
	sort(ALL(tmout));
	// cerr<<"Query\n";
	// for(auto i:tmin)cerr<<i<<' ';cerr<<'\n';
	// for(auto i:tmout)cerr<<i<<' ';cerr<<'\n';
	ll X=0;
	ll ans=0;
	for(auto i:tmin){
		while(SZ(tmout)&&tmout.back()+i>=0){
			tmout.pop_back();++X;
		}
		ans+=X;
	}
	return ans;
}

ll out;

struct CD{
	vi par,ban,sub;
	vpi V[MAXN];
	ll N;
	vi allouts,allins;
	CD(ll _N):N(_N){
		par.resize(N,-1);
		ban.resize(N,-1);
		sub.resize(N,-1);
	}
	void build(ll u,ll p,ll l){
		ll n=dfs1(u,-1);
		ll cent=dfs2(u,-1,n);
		par[cent]=p;
		ban[cent]=l;
		// cerr<<"Cent "<<cent<<'\n';
		allouts.clear();allins.clear();
		ll X=-1;
		for(auto v:V[cent])if(ban[v.f]==-1){
			tmout.clear();tmin.clear();

			ll ds=A[cent]-v.s;
			ll r=A[v.f]-v.s;
			dfs3(v.f,cent,ds,min(0LL,ds),max(0LL,-r),r);
			for(auto i:tmout)allouts.pb(i);
			for(auto i:tmin)allins.pb(i);
			ll t=res();
			// cerr<<"Sub "<<t<<'\n';
			X-=t;
		}
		tmout.clear();tmin.clear();
		tmin.pb(0);tmout.pb(0);
		for(auto i:allouts)tmout.pb(i);
		for(auto i:allins)tmin.pb(i);
		// cerr<<"Node "<<cent<<'\n';
		// for(auto i:tmout)cerr<<i<<' ';cerr<<'\n';
		// for(auto i:tmin)cerr<<i<<' ';cerr<<'\n';
		X += res();
		// cerr<<X<<'\n';
		out += X;

		for(auto v:V[cent])if(ban[v.f]==-1)build(v.f,cent,l+1);
	}
	ll dfs1(ll u,ll p){
		// ds is the current distance already completed
		sub[u]=1;
		for(auto v:V[u])if(v.f!=p&&ban[v.f]==-1){
			sub[u]+=dfs1(v.f,u);
		}
		return sub[u];
	}
	ll dfs2(ll u,ll p,ll n){
		for(auto v:V[u])if(v.f!=p&&ban[v.f]==-1){
			if(sub[v.f]>n/2)return dfs2(v.f,u,n);
		}
		return u;
	}
	void dfs3(ll u,ll p,ll ds,ll cs,ll req,ll surp){
		tmout.pb(cs);
		if(req<0)req=0;
		if(req==0)tmin.pb(surp);
		// req=min(0LL,req);
		for(auto v:V[u])if(v.f!=p&&ban[v.f]==-1){
			ll d=ds+A[u]-v.s;
			ll ns=surp+A[v.f]-v.s;
			dfs3(v.f,u,d,min(cs,d),req-A[v.f]+v.s,ns);
		}
	}
}*root;

ll N,a,b,w;

int main(){
	ios_base::sync_with_stdio(0);cin.tie(0);
	cin>>N;
	root=new CD(N);
	for(ll i=0;i<N;++i)cin>>A[i];
	for(ll i=1;i<N;++i){
		cin>>a>>b>>w;--a;--b;
		root->V[a].pb(b,w);
		root->V[b].pb(a,w);
	}
	root->build(0,-1,0);
	cout<<out;
}

• Subtask 1: 13 / 13
• Subtask 2: 13 / 13
• Subtask 3: 13 / 13
• Subtask 4: 13 / 13
• Subtask 5: 13 / 13
• Subtask 6: 13 / 13
• Subtask 7: 13 / 13
• Subtask 8: 13 / 13
• Subtask 9: 13 / 13
• Subtask 10: 13 / 13