Submission #244061

#	Time	Username	Problem	Language	Result	Execution time	Memory
244061		michao	Dreaming (IOI13_dreaming)	C++14	0 / 100	63 ms	15736 KiB

dreaming

#include <bits/stdc++.h>
#include "dreaming.h"
#define mp make_pair
#define pb push_back
#define ld long double
#define pii pair<int,int>
#define sz(x) (int)x.size()
#define piii pair<pii,pii>
#define precise cout<<fixed<<setprecision(10)
#define st first
#define nd second
#define ins insert
#define vi vector<int>
using namespace std;
const int MAX=1e5+5;
vector<pii>P[MAX];
int dist[MAX];
int ojciec[MAX];
vi mids;
bool O[MAX];

pii get_far(int u,int fa)
{
	pii akt=mp(dist[u],u);
	ojciec[u]=fa;
	O[u]=true;
  for (auto it:P[u])
  	if (it.st!=fa)
  	{
  		dist[it.st]=dist[u]+it.nd;
  		pii wez=get_far(it.st,u);
  		if (wez.st>akt.st)akt=wez;
  	}
  return akt;
}

int get_mid(int from,int ile)
{
	int maxi=0;
	while (from!=-1)
	{
		maxi=max(maxi,max(dist[from],ile-dist[from]));
		from=ojciec[from];
	}
	return maxi;
}

void func(int u)
{
	dist[u]=0;
	pii v=get_far(u,-1);
	int root=v.nd;
	dist[root]=0;
	pii znajdz=get_far(root,-1);
	int dist=znajdz.st;
	int wskaz=znajdz.nd;
  int ile=get_mid(wskaz,dist);
	mids.pb(ile);
}

int travelTime(int n,int m,int l,int a[],int b[],int t[])
{
	int ans=0;
	for (int i=0;i<m;i++)
	{
		int x=a[i];
		int y=b[i];
		int c=t[i];
		x++,y++;
		P[x].pb(mp(y,c));
		P[y].pb(mp(x,c));
	}
	
	for (int i=1;i<=n;i++)
	   if (!O[i])func(i);
	sort(mids.begin(),mids.end(),greater<int>());
	assert(sz(mids)!=0);
	assert(mids[0]!=0);
	if (sz(mids)>=1)ans=max(ans,mids[0]);
	if (sz(mids)>=2)ans=max(ans,mids[0]+mids[1]+l);
	if (sz(mids)>=3)ans=max(ans,mids[1]+mids[2]+l*2);
	return ans;
}

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