Submission #109437

#	Time	Username	Problem	Language	Result	Execution time	Memory
109437		amiratou	Dreaming (IOI13_dreaming)	C++14	24 / 100	122 ms	16632 KiB

dreaming

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

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