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Submission #132463

# Submission time Handle Problem Language Result Execution time Memory
132463 2019-07-18T23:07:33 Z arthurconmy Parachute rings (IOI12_rings) C++14
55 / 100
 4000 ms 81908 KB 
/* Arthur Conmy / arthurconmy */
#include <iostream>
#include <fstream>
#include <vector>
#include <string>
#include <cmath>
#include <algorithm>
#include <map>
#include <queue>
#include <bitset>
#include <random>
#include <stack>
#include <deque>
#include <chrono>
using namespace std;

const int MAXN=1000001; 

// GENERAL

int n;
vector<int> adj[MAXN];
int deg[MAXN];
int v_max=0;
int d_max=0;

// DSU

int link[MAXN];
int sz[MAXN];
int no_cycles=0;
int cycle_size=-1;

// DFS

bool vis[MAXN];
int cur_ignore=-1;

bool dfs(int b4, int u)
{
	vis[u]=1;

	for(auto v:adj[u])
	{
		if(v==cur_ignore) continue;
		if(vis[v] && v!=b4) return false;
		if(vis[v]) continue;

		bool b = dfs(u,v);
		if(!b) return false;
	}

	return true;
}

int emp(int a)
{
	while(a!=link[a]) a=link[a];
	return a;
}

void join(int a, int b)
{
	a=emp(a);
	b=emp(b);
	if(a==b) return;

	if(sz[a]<sz[b]) swap(a,b);
	sz[a]+=sz[b];
	link[b]=a;
}

void Init(int N)
{
	n=N;

	for(int i=0; i<n; i++)
	{
		link[i]=i;
		sz[i]=1;
	}
}

void Link(int A, int B)
{
	adj[A].push_back(B);
	adj[B].push_back(A);

	deg[A]++;
	deg[B]++;
	if(deg[B]>deg[A]) swap(A,B);

	if(deg[A] > d_max)
	{
		d_max=deg[A];
		v_max=A;
	}

	if(emp(A)==emp(B))
	{
		no_cycles++;
		cycle_size=sz[emp(A)];
	}

	join(A,B);
}

int CountCritical()
{
	if(d_max < 2)
	{
		return n;
	}

	if(d_max == 2)
	{
		if(no_cycles==0) return n;
		if(no_cycles>1) return 0;
		return cycle_size;
	}

	vector<int> trying = {v_max};

	if(d_max==3)
	{
		for(auto u:adj[v_max]) trying.push_back(u);
	}
	
	int no_that_work=0;
	
	for(auto v:trying)
	{
		// cout << v << endl;

		for(int i=0; i<n; i++) vis[i]=0;
		bool works=1;

		for(auto u:adj[v])
		{
			deg[u]--;
		}

		for(int i=1; i<MAXN; i++)
		{
			if(i==v) continue;
			if(deg[i] > 2) works=0;
		}

		for(auto u:adj[v])
		{
			deg[u]++;
		}

		if(!works) continue;

		// cout << works << endl;

		cur_ignore = v;

		for(int i=0; i<n; i++)
		{
			if(i==cur_ignore) continue;
			if(vis[i]) continue;
			bool b2 = dfs(-1,i);
			// cout << v << " " << i << " " << b2 << endl;
			if(!b2)
			{
				works=0;
				break;
			}
		}

		if(works) no_that_work++;
	}

	return no_that_work;
}

void thing()
{
	cout << CountCritical() << endl;
}

// int main()
// {
// 	#ifdef ARTHUR_LOCAL
// 		ifstream cin("input.txt");
// 	#endif

// 	Init(7);
// 	Link(1,2);
// 	Link(2,3);
// 	Link(2,0);
// 	Link(0,5);
// 	Link(3,5);
// 	Link(3,4);
// 	thing();
// }

Subtask #1
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 23800 KB Output is correct
2 Correct 27 ms 24056 KB Output is correct
3 Correct 28 ms 24056 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23928 KB Output is correct
6 Correct 25 ms 24056 KB Output is correct
7 Correct 28 ms 23928 KB Output is correct
8 Correct 25 ms 24056 KB Output is correct
9 Correct 30 ms 24184 KB Output is correct
10 Correct 31 ms 24184 KB Output is correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 451 ms 46384 KB Output is correct
2 Correct 1151 ms 59416 KB Output is correct
3 Correct 1142 ms 63856 KB Output is correct
4 Correct 1201 ms 67176 KB Output is correct
5 Correct 1193 ms 67044 KB Output is correct
6 Correct 1156 ms 65912 KB Output is correct
7 Correct 1128 ms 63516 KB Output is correct
8 Correct 1623 ms 65500 KB Output is correct
9 Correct 1479 ms 81908 KB Output is correct
10 Correct 878 ms 77816 KB Output is correct

Subtask #3
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 23800 KB Output is correct
2 Correct 27 ms 24056 KB Output is correct
3 Correct 28 ms 24056 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23928 KB Output is correct
6 Correct 25 ms 24056 KB Output is correct
7 Correct 28 ms 23928 KB Output is correct
8 Correct 25 ms 24056 KB Output is correct
9 Correct 30 ms 24184 KB Output is correct
10 Correct 31 ms 24184 KB Output is correct
11 Correct 127 ms 24220 KB Output is correct
12 Correct 56 ms 24500 KB Output is correct
13 Correct 174 ms 24444 KB Output is correct
14 Correct 105 ms 24312 KB Output is correct
15 Correct 129 ms 24312 KB Output is correct
16 Correct 29 ms 24440 KB Output is correct
17 Correct 328 ms 24520 KB Output is correct
18 Correct 135 ms 24696 KB Output is correct
19 Correct 30 ms 24440 KB Output is correct
20 Correct 190 ms 24568 KB Output is correct

Subtask #4
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 23800 KB Output is correct
2 Correct 27 ms 24056 KB Output is correct
3 Correct 28 ms 24056 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23928 KB Output is correct
6 Correct 25 ms 24056 KB Output is correct
7 Correct 28 ms 23928 KB Output is correct
8 Correct 25 ms 24056 KB Output is correct
9 Correct 30 ms 24184 KB Output is correct
10 Correct 31 ms 24184 KB Output is correct
11 Correct 127 ms 24220 KB Output is correct
12 Correct 56 ms 24500 KB Output is correct
13 Correct 174 ms 24444 KB Output is correct
14 Correct 105 ms 24312 KB Output is correct
15 Correct 129 ms 24312 KB Output is correct
16 Correct 29 ms 24440 KB Output is correct
17 Correct 328 ms 24520 KB Output is correct
18 Correct 135 ms 24696 KB Output is correct
19 Correct 30 ms 24440 KB Output is correct
20 Correct 190 ms 24568 KB Output is correct
21 Correct 48 ms 26044 KB Output is correct
22 Correct 58 ms 27000 KB Output is correct
23 Correct 69 ms 27892 KB Output is correct
24 Execution timed out 4019 ms 25568 KB Time limit exceeded
25 Halted 0 ms 0 KB -

Subtask #5
0 / 31.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 23800 KB Output is correct
2 Correct 27 ms 24056 KB Output is correct
3 Correct 28 ms 24056 KB Output is correct
4 Correct 23 ms 23800 KB Output is correct
5 Correct 24 ms 23928 KB Output is correct
6 Correct 25 ms 24056 KB Output is correct
7 Correct 28 ms 23928 KB Output is correct
8 Correct 25 ms 24056 KB Output is correct
9 Correct 30 ms 24184 KB Output is correct
10 Correct 31 ms 24184 KB Output is correct
11 Correct 451 ms 46384 KB Output is correct
12 Correct 1151 ms 59416 KB Output is correct
13 Correct 1142 ms 63856 KB Output is correct
14 Correct 1201 ms 67176 KB Output is correct
15 Correct 1193 ms 67044 KB Output is correct
16 Correct 1156 ms 65912 KB Output is correct
17 Correct 1128 ms 63516 KB Output is correct
18 Correct 1623 ms 65500 KB Output is correct
19 Correct 1479 ms 81908 KB Output is correct
20 Correct 878 ms 77816 KB Output is correct
21 Correct 127 ms 24220 KB Output is correct
22 Correct 56 ms 24500 KB Output is correct
23 Correct 174 ms 24444 KB Output is correct
24 Correct 105 ms 24312 KB Output is correct
25 Correct 129 ms 24312 KB Output is correct
26 Correct 29 ms 24440 KB Output is correct
27 Correct 328 ms 24520 KB Output is correct
28 Correct 135 ms 24696 KB Output is correct
29 Correct 30 ms 24440 KB Output is correct
30 Correct 190 ms 24568 KB Output is correct
31 Correct 48 ms 26044 KB Output is correct
32 Correct 58 ms 27000 KB Output is correct
33 Correct 69 ms 27892 KB Output is correct
34 Execution timed out 4019 ms 25568 KB Time limit exceeded
35 Halted 0 ms 0 KB -