제출 #542344

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
542344		inksamurai	Parkovi (COCI22_parkovi)	C++17	110 / 110	1885 ms	57320 KiB

Main

#include <bits/stdc++.h>
#define int ll
using namespace std;
#define rep(i,n) for(int i=0;i<n;i++)
#define rng(i,x,n) for(int i=x;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define vec(...) vector<__VA_ARGS__>
#define _3ulnVOy ios::sync_with_stdio(0),cin.tie(0)
typedef long long ll;
using pii=pair<int,int>;
using vi=vector<int>;
void print(){cout<<"\n";}
template<class h,class...t>
void print(const h&v,const t&...u){cout<<v<<' ',print(u...);}
// e

const int inf=1e9+11;
const ll lnf=1e15+11;
using pll=pair<ll,ll>;
using vp=vec(pll);

signed main(){
_3ulnVOy;
	int n,k;
	cin>>n>>k;
	vec(vp) adj(n);
	rep(i,n-1){
		int u,v,w;
		cin>>u>>v>>w;
		u-=1,v-=1;
		adj[u].pb({v,w});
		adj[v].pb({u,w});
	}

	int cnt=0;
	vi pns;
	auto dfs=[&](auto self,int v,int par,int can)->pll{
		pll now={0,-lnf}; 
		vec(pair<int,pll>) cands;
		for(auto e:adj[v]){
			auto [u,w]=e;
			if(u==par) continue;
			pll nep=self(self,u,v,can);
			if(nep.fi+w>can){
				pns.pb(u);
				now.se=max(now.se,can-w);
				cnt+=1;
			}else{
				now.se=max(now.se,nep.se-w);
				cands.pb({w,nep});
			}
		}
		for(auto tp:cands){
			ll w=tp.fi;
			pll p=tp.se;
			now.fi=max(now.fi,p.fi+w);
		}
		if(now.fi<=now.se){
			now.fi=-lnf;
		}
		return now;
	};

	auto quq=[&](int x)->bool{
		cnt=0;
		pns.clear();
		pll p=dfs(dfs,0,-1,x);
		if(p.fi!=-lnf){
			cnt+=1;
			pns.pb(0);
		}
		return cnt<=k;
		// print("\n...",cnt);
	};

	int c;
	{
		int l=1,r=lnf;
		while(l<=r){
			int m=(l+r)/2;
			if(quq(m)){
				c=m;
				r=m-1;
			}else{
				l=m+1;
			}
		}
		quq(c);
	}

	{
		vi usd(n,0);
		rep(i,sz(pns)){
			usd[pns[i]]=1;
		}
		rep(i,n){
			if(!usd[i] and sz(pns)<k){
				pns.pb(i);
			}
		}
	}

	print(c);
	for(auto v:pns){
		cout<<v+1<<" ";
	}
	print();
//
	return 0;
}

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