Submission #824697

#	Time	Username	Problem	Language	Result	Execution time	Memory
824697		caganyanmaz	Split the Attractions (IOI19_split)	C++17	40 / 100	78 ms	21804 KiB

split

#include <bits/stdc++.h>
#define pb push_back
#include "split.h"

using namespace std;
constexpr static int MXN = 1e5;
vector<int> g[MXN];
int subsize[MXN],  n;
vector<int> res;

array<array<int, 2>, 3> arr;
array<int, 3> counter;

void dfs2(int node, int parent, int val)
{
	if (counter[val] == arr[val][0])
		return;
	counter[val]++;
	res[node] = arr[val][1];
	for (int c : g[node])
		if (c != parent)
			dfs2(c, node, val);
}

bool dfs1(int node, int parent)
{
	subsize[node] = 1;
	for (int c : g[node])
	{
		if (c != parent)
		{
			bool out = dfs1(c, node);
			if (out)
				return true;
			subsize[node]  += subsize[c];
		}
	}
		
	if (subsize[node] >= arr[0][0] && n - subsize[node] >= arr[1][0])
	{
		dfs2(node, parent, 0);
		dfs2(parent, node, 1);
		return true;
	}
	else if (subsize[node] >= arr[1][0] && n - subsize[node] >= arr[0][0])
	{
		dfs2(node, parent, 1);
		dfs2(parent, node, 0);
		return true;
	}
	return false;
}

vector<int> rg[MXN];
bitset<MXN> visited;

void create_dfs_tree(int node, int parent)
{
	visited[node] = true;
	if (parent != -1)
	{
		g[node].pb(parent);
		g[parent].pb(node);
	}
	for (int c : rg[node])
		if (!visited[c])
			create_dfs_tree(c, node);
}

vector<int> find_split(int _n, int a, int b, int c, vector<int> p, vector<int> q)
{
	n = _n;
	res = vector<int>(n, 0);
	for (int i = 0; i < p.size(); i++)
	{
		rg[p[i]].pb(q[i]);
		rg[q[i]].pb(p[i]);
	}
	arr[0] = {a, 1};
	arr[1] = {b, 2};
	arr[2] = {c, 3};
	sort(arr.begin(), arr.end());
	
	if (n >= 2500)
	{
		create_dfs_tree(0, -1);
		if (dfs1(0, -1))
			for (int i = 0; i < n; i++)
				if (!res[i])
					res[i] = arr[2][1];
		return res;
	}
	else
	{
		for (int j = 0; j < n; j++)
		{
			create_dfs_tree(j, -1);
			if (dfs1(j, -1))
			{
				for (int i = 0; i < n; i++)
					if (!res[i])
						res[i] = arr[2][1];
				return res;
			}
		
		}
	}
	return res;
}

Compilation message (stderr)

split.cpp: In function 'std::vector<int> find_split(int, int, int, int, std::vector<int>, std::vector<int>)':
split.cpp:74:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   74 |  for (int i = 0; i < p.size(); i++)
      |                  ~~^~~~~~~~~~

• Subtask 1: 7 / 7
• Subtask 2: 11 / 11
• Subtask 3: 22 / 22
• Subtask 4: 0 / 24
• Subtask 5: 0 / 36