Submission #109443

#	Time	Username	Problem	Language	Result	Execution time	Memory
109443		amiratou	꿈 (IOI13_dreaming)	C++14	65 / 100	142 ms	16364 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"
using namespace std;
#define fi first
#define se second
#define INF (int)(1e9)
#define ll long long
vector<vector<pair<ll,ll> > > vec;
bool vis[100005];
ll maxi=0,a,idx=0;
vector<pair<ll,ll> > tree_d;
pair<ll,ll> p[100005],center[100005];
vector<ll> nodes;
void dfs(ll node,ll d){
	nodes.push_back(node);
	if(d>maxi)
		a=node,maxi=d;
	vis[node]=1;
	for(auto child:vec[node])
		if(child.fi!=p[node].fi){
			p[child.fi]={node,child.se};
			dfs(child.fi,d+child.se);
		}
}
pair<ll,ll> findCenter(ll node){
	maxi=0;
	dfs(node,0);
	for(auto i:nodes)
		p[i]={-1,-1};
	nodes.clear();
	ll B=a,sum=0,mini=INF,c=node,sh=INF;
	maxi=0;
	if(B!=-1)
		dfs(B,0);
	nodes.clear();
	for(;a!=-1;sum+=p[a].se,a=p[a].fi){
		if(abs(maxi/2-sum)<mini)
			mini=abs(maxi/2-sum),c=a,sh=sum;
		if(maxi%2&&abs((maxi/2)+1-sum)<mini)
			mini=abs((maxi/2)+1-sum),c=a,sh=sum;
	}
	tree_d.push_back({maxi,idx});
	return {c,max(maxi-sh,0LL)};
}
int travelTime(int N, int M, int L, int A[], int B[], int T[]) {
	vec.resize(N);
	memset(p,-1,sizeof p);
	for (ll i = 0; i < M; ++i)
	{
		vec[A[i]].push_back({B[i],T[i]});
		vec[B[i]].push_back({A[i],T[i]});
	}
	for (ll i = 0; i < N; ++i)
		if(!vis[i])
			center[idx++]=findCenter(i);
	sort(tree_d.begin(),tree_d.end(),greater<pair<ll,ll> >());
	for (ll i = 1; i < idx; ++i)
	{
		vec[center[tree_d[i].se].fi].push_back({center[tree_d[0].se].fi,L});
		vec[center[tree_d[0].se].fi].push_back({center[tree_d[i].se].fi,L});
	}
	maxi=0;
	memset(p,-1,sizeof p);
	dfs(0,0);
	nodes.clear();
	ll b=a;
	if(b==-1)return maxi;
	memset(p,-1,sizeof p);
	maxi=0;
	dfs(b,0);
    return maxi;
}

• Subtask 1: 14 / 14
• Subtask 2: 10 / 10
• Subtask 3: 23 / 23
• Subtask 4: 18 / 18
• Subtask 5: 0 / 12
• Subtask 6: 0 / 23