Submission #1223361

#	Time	Username	Problem	Language	Result	Execution time	Memory
1223361		_rain_	Sjekira (COCI20_sjekira)	C++20	110 / 110	46 ms	2924 KiB

sjekira

#include<bits/stdc++.h>
using namespace std;
typedef long long LL;

const int N=(int)1e5;
	int par[N+2],sz[N+2],mx[N+2];
	int t[N+2],u[N+2],v[N+2];
	int n;
	LL ans=0;
	vector<int>edg;
	
	int Find(int u){
		return par[u]==u?par[u]:par[u]=Find(par[u]);
	}
	void unite(int u,int v){
		u=Find(u),v=Find(v);
		if (u==v) return;
		if (sz[u]<sz[v]) swap(u,v);
		par[v]=u , sz[u]+=sz[v];
		t[u]=max(t[u],t[v]);
		return;
	}

int main(){
	ios::sync_with_stdio(false);
	cin.tie(0) ; cout.tie(0);
	#define task "main"
	if (fopen(task".inp","r")){
		freopen(task".inp","r",stdin);
		freopen(task".out","w",stdout);
	}
	
	cin>>n;
	for(int i=1;i<=n;++i) sz[i]=1,par[i]=i;
	for(int i=1;i<=n;++i) cin>>t[i];
	for(int i=1;i<n;++i){
		cin>>u[i]>>v[i];
		edg.push_back(i);
	}
	sort(edg.begin(),edg.end(),[&](int x,int y){
		return max(t[u[x]],t[v[x]])<max(t[u[y]],t[v[y]]);	
	});
	ans=0;
	for(auto&i:edg){
		ans+=t[Find(u[i])]+t[Find(v[i])];
		unite(u[i],v[i]);
	}
	cout<<ans;
	return 0;
}

Compilation message (stderr)

sjekira.cpp: In function 'int main()':
sjekira.cpp:29:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |                 freopen(task".inp","r",stdin);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
sjekira.cpp:30:24: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |                 freopen(task".out","w",stdout);
      |                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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