Submission #897391

#	Time	Username	Problem	Language	Result	Execution time	Memory
897391		Muhammad_Aneeq	Dreaming (IOI13_dreaming)	C++17	0 / 100	53 ms	15700 KiB

dreaming

#include <vector>
#include <algorithm>
#include "dreaming.h"
using namespace std;
int const N=1e5+10;
vector<pair<int,int>>nei[N]={};
vector<int>heads;
bool vis[N]={};
int cost[N]={};
void dfs(int n)
{
	vis[n]=1;
	for (auto [i,w]:nei[n])
	{
		if (!vis[i])
		{
			cost[n]+=w;
			dfs(i);
			cost[n]+=cost[i];
		}
	}
}
vector<pair<int,int>>cur={};
void getroot(int n,int pa,int root)
{
	int f=0;
	for (auto [i,w]:nei[n])
	{
		if (i!=pa)
		{
			f=max(f,cost[i]);
			getroot(i,n,root);
		}
		else
			f=max(f,cost[pa]-cost[n]);
	}
	cur.push_back({f,n});
}
void dfs1(int n,int m=-1)
{
	for (auto [i,w]:nei[n])
		if (i!=m)
		{
			cost[i]+=cost[n];
			cost[i]+=w;
			dfs1(i,n);
		}
}
int travelTime(int n, int m, int l, int a[], int b[], int t[])
{
	for (int i=0;i<m;i++)
	{
		nei[a[i]].push_back({b[i],t[i]});
		nei[b[i]].push_back({a[i],t[i]});
	}
	for (int i=0;i<n;i++)
	{
		if (!vis[i])
		{
			heads.push_back(i);
			dfs(i);
		}
	}
	for (int i=0;i<n;i++)
		vis[i]={};
	vector<pair<int,int>>new_head;
	for (auto i:heads)
	{
		getroot(i,-1,i);
		sort(begin(cur),end(cur));
		new_head.push_back(cur[0]);
		cur={};
	}
	sort(begin(new_head),end(new_head));
	reverse(begin(new_head),end(new_head));
	for (int i=1;i<new_head.size();i++)
	{
		nei[new_head[0].second].push_back({new_head[i].second,l});
		nei[new_head[i].second].push_back({new_head[0].second,l});
	}
	for (int i=0;i<n;i++)
		cost[i]=0;
	dfs1(0);
	new_head={};
	for (int i=0;i<n;i++)
	{
		new_head.push_back({cost[i],i});
		cost[i]=0;
	}
	sort(begin(new_head),end(new_head));
	reverse(begin(new_head),end(new_head));
	dfs1(new_head[0].second);
	new_head={};
	for (int i=0;i<n;i++)
	{
		new_head.push_back({cost[i],i});
		cost[i]=0;
	}
	sort(begin(new_head),end(new_head));
	reverse(begin(new_head),end(new_head));
	return new_head[0].first;
}

Compilation message (stderr)

dreaming.cpp: In function 'int travelTime(int, int, int, int*, int*, int*)':
dreaming.cpp:76:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   76 |  for (int i=1;i<new_head.size();i++)
      |               ~^~~~~~~~~~~~~~~~

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