Submission #526536

#	Time	Username	Problem	Language	Result	Execution time	Memory
526536		jwvg0425	Parachute rings (IOI12_rings)	C++17	20 / 100	4048 ms	49004 KiB

rings

#include <stdio.h>
#include <vector>
#include <queue>
#include <algorithm>
#include <iostream>
#include <string>
#include <bitset>
#include <map>
#include <set>
#include <tuple>
#include <string.h>
#include <math.h>
#include <random>
#include <functional>
#include <assert.h>
#include <math.h>
#define all(x) (x).begin(), (x).end()
#define xx first
#define yy second

using namespace std;

template<typename T, typename Pr = less<T>>
using pq = priority_queue<T, vector<T>, Pr>;
using i64 = long long int;
using ii = pair<int, int>;
using ii64 = pair<i64, i64>;

int n;

void Init(int n_)
{
	n = n_;
}

vector<int> edge[1000005];

void Link(int a, int b)
{
	edge[a].push_back(b);
	edge[b].push_back(a);
}

bool isCritical(int x)
{
	vector<int> deg(n);

	for (int i = 0; i < n; i++)
	{
		deg[i] = edge[i].size();
		for (auto& e : edge[i])
		{
			if (e == x)
				deg[i]--;
		}
	}

	// 전부 deg 2 이하인지 확인
	for (int i = 0; i < n; i++)
	{
		if (i == x)
			continue;

		if (deg[i] > 2)
			return false;
	}

	// deg 1에서 시작해서 전부 방문가능한지 확인(chain)
	vector<bool> vis(n);

	queue<int> q;

	for (int i = 0; i < n; i++)
	{
		if (i == x)
			continue;

		if (deg[i] == 0)
			vis[i] = true;

		if (deg[i] != 1)
			continue;
		q.push(i);

		vis[i] = true;
	}

	while (!q.empty())
	{
		auto now = q.front();
		q.pop();

		for (auto& e : edge[now])
		{
			if (e == x || vis[e])
				continue;

			vis[e] = true;
			q.push(e);
		}
	}

	for (int i = 0; i < n; i++)
	{
		if (i == x)
			continue;

		if (!vis[i])
			return false;
	}

	return true;
}

int CountCritical()
{
	int ans = 0;
	for (int i = 0; i < n; i++)
	{
		if (isCritical(i))
			ans++;
	}

	return ans;
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 17
• Subtask 3: 0 / 18
• Subtask 4: 0 / 14
• Subtask 5: 0 / 31