제출 #864070

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
864070		MilosMilutinovic	Sjekira (COCI20_sjekira)	C++14	110 / 110	84 ms	11464 KiB

sjekira

#include<bits/stdc++.h>

#define pb push_back
#define fi first
#define se second
#define mp make_pair

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
typedef long double ld;

template <typename T> bool chkmin(T &x,T y){return x>y?x=y,1:0;}
template <typename T> bool chkmax(T &x,T y){return x<y?x=y,1:0;}

int readint(){
	int x=0,f=1; char ch=getchar();
	while(ch<'0'||ch>'9'){if(ch=='-')f=-1;ch=getchar();}
	while(ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
	return x*f;
}

int n,a[100005],v[200005],nxt[200005],h[100005],tot,ord[100005],fa[100005],mx[100005];
vector<pii> edg;
set<pii> st;
ll ans=0;

void addedge(int x,int y){
	v[++tot]=y; nxt[tot]=h[x]; h[x]=tot;
	v[++tot]=x; nxt[tot]=h[y]; h[y]=tot;
}

void ins(int x,int y){
	if(x>y) swap(x,y);
	if(st.find(mp(x,y))!=st.end()) return;
	st.insert(mp(x,y));
	edg.pb(mp(x,y));
}

int getf(int x){return fa[x]==x?x:fa[x]=getf(fa[x]);}

void merge(int x,int y){
	x=getf(x); y=getf(y);
	ans+=mx[x];
	ans+=mx[y];
	fa[y]=x;
	mx[x]=max(mx[x],mx[y]);
}

int main(){
	n=readint();
	for(int i=1;i<=n;i++) a[i]=readint();
	for(int i=1;i<n;i++) addedge(readint(),readint());
	for(int i=1;i<=n;i++) ord[i]=i;
	sort(ord+1,ord+n+1,[&](int i,int j){return a[i]>a[j];});
	for(int i=1;i<=n;i++){
		int x=ord[i];
		for(int p=h[x];p;p=nxt[p]) ins(x,v[p]);
	}
	reverse(edg.begin(),edg.end());
	for(int i=1;i<=n;i++) fa[i]=i,mx[i]=a[i];
	for(auto&p:edg) merge(p.fi,p.se);
	printf("%lld\n",ans);
	return 0;
}

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