Submission #780128

#	Time	Username	Problem	Language	Result	Execution time	Memory
780128		CESxRhino	Factories (JOI14_factories)	C++14	0 / 100	29 ms	24148 KiB

factories

#include "factories.h"
#include <bits/stdc++.h>
#define ii pair<int,int>
#define f first
#define s second
#define pb push_back
#define ll long long
#define endl '\n'
using namespace std;
vector<ii> w[500005];
vector<pair<int,ll> > w2[500005];
int level[500005][33];
int First[500005];
int End[500005];
ll dist[500005];
int DFStime;
int color[500005];
int s[500005];
int t[500005];
ll mindist;
void DFS(int u,int par)
{
	First[u] = ++DFStime;
	level[u][0] = par;
	for(int i = 1;i < 33;i++)
	{
		level[u][i] = level[level[u][i - 1]][i - 1];
	}
	for(auto v:w[u])
	{
		if(v.first == par)
		{
			continue;
		}
		dist[v.first] = dist[u] + v.second;
		DFS(v.first,u);
	}
	End[u] = DFStime;
}
bool check(int u,int v)
{
	return (First[u] <= First[v] and End[v] <= End[u]);
}
int LCA(int u,int v)
{
	if(check(u,v))
	{
		return u;
	}
	if(check(v,u))
	{
		return v;
	}
	for(int i = 32;i >= 0;i--)
	{
		if(!check(level[u][i],v))
		{
			u = level[u][i];
		}
	}
	return level[u][0];
}
void Init(int n, int a[], int b[], int d[])
{
    for(int i = 0;i < n - 1;i++)
    {
        w[a[i]].pb({b[i],d[i]}),
        w[b[i]].pb({a[i],d[i]});	
	}
    DFS(0,0);
}
void edge(int u,int v)
{
	if(u == v)
	{
		return;
	}
	ll d = abs(dist[u] - dist[v]);
	w2[u].push_back({v,d});
	w2[v].push_back({u,d});
}
int virtual_tree(vector<int> &nodes)
{
	sort(nodes.begin(),nodes.end(),[](int &i, int &j){return (First[i] < First[j]);});
	for(int i = (int) (nodes.size()) - 2;i >= 0;i--)
	{
		int res = LCA(nodes[i],nodes[i + 1]);
		nodes.push_back(res);
	}
	sort(nodes.begin(),nodes.end(),[](int &i, int &j){return (First[i] < First[j]);});
	vector<int> s;
	s.push_back(nodes[0]);
	for(int i = 1;i < nodes.size();i++)
	{
		while(!check(s.back(),nodes[i]))
		{	
			edge(s.back(),s[s.size() - 2]);
			s.pop_back();
		}
		s.push_back(nodes[i]);
	}
	while(s.size() > 1)
	{
		edge(s.back(),s[s.size() - 2]);
		s.pop_back();
	}
	return s[0];
}
ii DFS2(int u,int par)
{
	ll min1 = 1e18;
	ll min2 = 1e18;
	if(color[u] == 1)
	{
		min1 = 0;
	}
	else if(color[u] == 2)
	{
		min2 = 0;
	}
	for(auto v:w2[u])
	{
		if(v.first != par)
		{
			ii tree = DFS2(v.first,u);
			min1 = min(min1,v.second + tree.first);
			min2 = min(min2,v.second + tree.second);
		}
	}
	mindist = min(mindist,min1 + min2);
	return {min1,min2};
}
long long Query(int n, int x[], int m, int y[])
{
	vector<int> nodes;
	for(int i = 0;i < n;i++)
	{
		nodes.push_back(x[i]);
		color[x[i]] = 1;
	}
	for(int i = 0;i < n;i++)
	{
		nodes.push_back(y[i]);
		color[y[i]] = 2;
	}
	int r = virtual_tree(nodes);
	mindist = 1e18;
	DFS2(r,r);
	for(auto x:nodes)
        w2[x].clear(),
        color[x] = 0;
	return mindist;
}	

Compilation message (stderr)

factories.cpp: In function 'int virtual_tree(std::vector<int>&)':
factories.cpp:93:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   93 |  for(int i = 1;i < nodes.size();i++)
      |                ~~^~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 18
• Subtask 3: 0 / 67