제출 #488050

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
488050		inksamurai	Sjekira (COCI20_sjekira)	C++17	110 / 110	111 ms	20440 KiB

sjekira

#include <bits/stdc++.h>
#define fi first
#define se second
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) a.begin(),a.end()
#define rep(i,n) for(int i=0;i<n;i++)
#define crep(i,x,n) for(int i=x;i<n;i++)
#define drep(i,n) for(int i=n-1;i>=0;i--)
#define vec(...) vector<__VA_ARGS__>
#define _3HaBFkZ ios_base::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
typedef long long ll;
typedef long double ld;
using pii=pair<int,int>;
using vi=vector<int>;

struct dsu{
	int n,size_;
	vector<int> par,siz,maxima;
	dsu(int m,vi a){
		init(m,a);
	}
	void init(int m,vi a){
		n=m;
		size_=m;
		par.resize(n,0);
		siz.resize(n,0);
		maxima.resize(n,0);
		for(int i=0;i<n;i++){
			par[i]=i;
			siz[i]=1;
			maxima[i]=a[i];
		}
	}
	void merge(int x,int y,int type=0){
		int a=parent(x),b=parent(y);
		if(a==b) return;
		size_--;
		if(siz[a]>siz[b]) {
			siz[a]+=siz[b];
			par[b]=a;
			maxima[a]=max(maxima[a],maxima[b]);
		}else{
			siz[b]+=siz[a];
			par[a]=b;
			maxima[b]=max(maxima[b],maxima[a]);
		}
	}
	int parent(int x){
		return par[x]==x?x:parent(par[x]);
	}
	bool same(int x, int y){
		return parent(x)==parent(y);
	}
	int size(){
		return size_;
	}
};

int main(){
_3HaBFkZ;
	int n;
	cin>>n;
	vi a(n);
	rep(i,n){
		cin>>a[i];
	}
	vec(set<int>) adj(n);
	rep(i,n-1){
		int u,v;
		cin>>u>>v;
		u--,v--;
		adj[u].insert(v);
		adj[v].insert(u);
	}
	vec(pii) rbts;
	rep(i,n){
		rbts.pb({a[i],i});
	}
	sort(all(rbts));
	reverse(all(rbts));
	vec(pii) prcs;
	rep(i,sz(rbts)){
		int v=rbts[i].se;
		ll val=rbts[i].fi;
		for(auto u : adj[v]){
			prcs.pb({v,u});
			adj[u].erase(v);
		}
	}
	reverse(all(prcs));
	dsu uf(n,a);
	ll ans=0;
	rep(i,sz(prcs)){
		int v=prcs[i].fi,u=prcs[i].se;
		int par1=uf.parent(v),par2=uf.parent(u);
		ans+=uf.maxima[par1];
		ans+=uf.maxima[par2];
		uf.merge(u,v);
	}
	cout<<ans<<"\n";
//	
	return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

sjekira.cpp: In function 'int main()':
sjekira.cpp:86:6: warning: unused variable 'val' [-Wunused-variable]
   86 |   ll val=rbts[i].fi;
      |      ^~~

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