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Submission #1080457

# Submission time Handle Problem Language Result Execution time Memory
1080457 2024-08-29T10:08:00 Z Elias Simurgh (IOI17_simurgh) C++17
30 / 100
 3000 ms 217140 KB 
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")

#include <bits/stdc++.h>

using namespace std;

#define ll long long

#ifdef _DEBUG
std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v);
int count_common_roads(const std::vector<int> &r);
#else
#include "simurgh.h"
#endif

vector<int> U, V;
int N;

set<int> trash_edges;

vector<int> par;

int find_parent(int a)
{
	if (par[a] == a)
		return a;
	return par[a] = find_parent(par[a]);
}

bool unite(int a, int b)
{
	if (rand() % 2)
		swap(a, b);

	a = find_parent(a), b = find_parent(b);
	if (a == b)
		return false;
	par[b] = a;
	return true;
}

void reset_parent()
{
	par = vector<int>(N);
	for (int i = 0; i < N; i++)
		par[i] = i;
}

void dfs_spanning(set<int> &edges)
{
	reset_parent();

	for (int i : edges)
	{
		unite(U[i], V[i]);
	}

	for (int i = 0; i < U.size(); i++)
	{
		if (!trash_edges.count(i))
			if (unite(U[i], V[i]))
				edges.insert(i);
	}
}

bool dfs_cycle(int i, int p, vector<vector<pair<int, int>>> &adj, vector<int> &vis, set<int> &edges)
{
	vis[i] = true;

	for (auto [c, j] : adj[i])
	{
		if (c == p)
			continue;
		if (vis[c] || dfs_cycle(c, i, adj, vis, edges))
		{
			assert(!trash_edges.count(j));
			edges.insert(j);
			return true;
		}
	}
	return false;
}

map<set<int>, int> results;

int cnt_common_set(set<int> &a)
{
	if (results.count(a))
		return results[a];
	return results[a] = count_common_roads(vector(a.begin(), a.end()));
}

vector<vector<pair<int, int>>> build_adj(set<int> &edges)
{
	vector<vector<pair<int, int>>> adj(N);
	for (int i : edges)
	{
		adj[U[i]].push_back({V[i], i});
		adj[V[i]].push_back({U[i], i});
	}
	return adj;
}

std::vector<int> find_roads(int n, std::vector<int> u, std::vector<int> v)
{
	U = u, V = v;
	N = n;

	set<int> edges;
	set<int> fancy_edges;

	vector<int> visited(n);

	dfs_spanning(edges);

	int base_count = cnt_common_set(edges);

	for (int i = 0; i < u.size(); i++)
	{
		if (edges.count(i) || fancy_edges.count(i) || trash_edges.count(i))
			continue;

		edges.insert(i);

		auto adj = build_adj(edges);
		visited = vector<int>(n);

		set<int> cycle_edges;

		dfs_cycle(u[i], -1, adj, visited, cycle_edges);

		cycle_edges.erase(i);

		set<int> stayed;
		int action_stayed = 0;

		for (int edge : cycle_edges)
		{
			if (fancy_edges.count(edge))
				continue;

			edges.erase(edge);

			int new_count = cnt_common_set(edges);

			if (new_count > base_count)
			{
				action_stayed = 1;
				trash_edges.insert(edge);
				break;
			}
			else if (new_count < base_count)
			{
				action_stayed = -1;
				edges.insert(edge);
				fancy_edges.insert(edge);
				trash_edges.insert(i);
				edges.erase(i);
				break;
			}
			else
			{
				stayed.insert(edge);
				edges.insert(edge);
			}
		}

		if (action_stayed == 0)
		{
			trash_edges.insert(i);
			edges.erase(i);
			for (int edge : stayed)
			{
				trash_edges.insert(edge);
				edges.erase(edge);
			}
		}
		else if (action_stayed == 1)
		{
			for (int edge : stayed)
			{
				fancy_edges.insert(edge);
			}
		}
		else if (action_stayed == -1)
		{
			for (int edge : stayed)
			{
				trash_edges.insert(edge);
				edges.erase(edge);
			}
		}

		dfs_spanning(edges);
		base_count = cnt_common_set(edges);
	}

	for (auto edge : edges)
		fancy_edges.insert(edge);

	return vector(fancy_edges.begin(), fancy_edges.end());
}

#ifdef _DEBUG

using namespace std;

static int MAXQ = 30000;

static int n, m, q = 0;
static vector<int> u, v;
static vector<bool> goal;
static vector<int> parent;

static int find(int node)
{
	return (parent[node] == node ? node : parent[node] = find(parent[node]));
}

static bool merge(int v1, int v2)
{
	v1 = find(v1);
	v2 = find(v2);
	if (v1 == v2)
		return false;
	parent[v1] = v2;
	return true;
}

static void wrong_answer()
{
	printf("NO\n");
	exit(0);
}

static bool is_valid(const vector<int> &r)
{
	if (int(r.size()) != n - 1)
		return false;

	for (int i = 0; i < n - 1; i++)
		if (r[i] < 0 || r[i] >= m)
			return false;

	parent.resize(n);
	for (int i = 0; i < n; i++)
	{
		parent[i] = i;
	}
	for (int i = 0; i < n - 1; i++)
	{
		if (!merge(u[r[i]], v[r[i]]))
		{
			return false;
		}
	}
	return true;
}

static int _count_common_roads_internal(const vector<int> &r)
{
	if (!is_valid(r))
		wrong_answer();

	int common = 0;
	for (int i = 0; i < n - 1; i++)
	{
		bool is_common = goal[r[i]];
		if (is_common)
			common++;
	}

	return common;
}

int count_common_roads(const vector<int> &r)
{
	q++;
	if (q > MAXQ) {
		cout << "Too many queries!!!\n";
		wrong_answer();
	}

	return _count_common_roads_internal(r);
}

int main()
{
	// cin.tie(0);
	// ios_base::sync_with_stdio(false);

	freopen("/home/elias/Downloads/ioi2017tests/simurgh/tests/3-01.in", "r", stdin);

	string trash;
	cin >> trash;

	assert(2 == scanf("%d %d", &n, &m));
	assert(1 == scanf("%d", &MAXQ));

	u.resize(m);
	v.resize(m);

	for (int i = 0; i < m; i++)
		assert(2 == scanf("%d %d", &u[i], &v[i]));

	goal.resize(m, false);

	for (int i = 0; i < n - 1; i++)
	{
		int id;
		assert(1 == scanf("%d", &id));
		goal[id] = true;
	}

	vector<int> result = find_roads(n, u, v);

	if (_count_common_roads_internal(result) != n - 1)
		wrong_answer();

	printf("OK\n");
	for (int i = 0; i < (int)result.size(); i++)
	{
		if (i)
			printf(" ");
		printf("%d", result[i]);
	}
	printf("\n");

	cout << q << "\n";

	return 0;
}

#endif

Compilation message

simurgh.cpp: In function 'void dfs_spanning(std::set<int>&)':
simurgh.cpp:59:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   59 |  for (int i = 0; i < U.size(); i++)
      |                  ~~^~~~~~~~~~
simurgh.cpp: In function 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:119:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  119 |  for (int i = 0; i < u.size(); i++)
      |                  ~~^~~~~~~~~~

Subtask #1
13.0 / 13.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 344 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 1 ms 348 KB correct

Subtask #2
17.0 / 17.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 344 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 1 ms 348 KB correct
14 Correct 28 ms 2644 KB correct
15 Correct 32 ms 1880 KB correct
16 Correct 56 ms 2388 KB correct
17 Correct 20 ms 2484 KB correct
18 Correct 6 ms 1112 KB correct
19 Correct 34 ms 2640 KB correct
20 Correct 27 ms 2140 KB correct
21 Correct 16 ms 2140 KB correct
22 Correct 16 ms 588 KB correct
23 Correct 14 ms 348 KB correct
24 Correct 13 ms 604 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 15 ms 600 KB correct
27 Correct 14 ms 604 KB correct
28 Correct 4 ms 348 KB correct
29 Correct 2 ms 348 KB correct
30 Correct 14 ms 600 KB correct
31 Correct 14 ms 604 KB correct
32 Correct 14 ms 604 KB correct
33 Correct 16 ms 600 KB correct

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 344 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 1 ms 348 KB correct
14 Correct 28 ms 2644 KB correct
15 Correct 32 ms 1880 KB correct
16 Correct 56 ms 2388 KB correct
17 Correct 20 ms 2484 KB correct
18 Correct 6 ms 1112 KB correct
19 Correct 34 ms 2640 KB correct
20 Correct 27 ms 2140 KB correct
21 Correct 16 ms 2140 KB correct
22 Correct 16 ms 588 KB correct
23 Correct 14 ms 348 KB correct
24 Correct 13 ms 604 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 15 ms 600 KB correct
27 Correct 14 ms 604 KB correct
28 Correct 4 ms 348 KB correct
29 Correct 2 ms 348 KB correct
30 Correct 14 ms 600 KB correct
31 Correct 14 ms 604 KB correct
32 Correct 14 ms 604 KB correct
33 Correct 16 ms 600 KB correct
34 Execution timed out 3048 ms 171088 KB Time limit exceeded
35 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Execution timed out 3100 ms 217140 KB Time limit exceeded
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 344 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 0 ms 348 KB correct
7 Correct 0 ms 348 KB correct
8 Correct 1 ms 348 KB correct
9 Correct 0 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 1 ms 348 KB correct
14 Correct 28 ms 2644 KB correct
15 Correct 32 ms 1880 KB correct
16 Correct 56 ms 2388 KB correct
17 Correct 20 ms 2484 KB correct
18 Correct 6 ms 1112 KB correct
19 Correct 34 ms 2640 KB correct
20 Correct 27 ms 2140 KB correct
21 Correct 16 ms 2140 KB correct
22 Correct 16 ms 588 KB correct
23 Correct 14 ms 348 KB correct
24 Correct 13 ms 604 KB correct
25 Correct 1 ms 348 KB correct
26 Correct 15 ms 600 KB correct
27 Correct 14 ms 604 KB correct
28 Correct 4 ms 348 KB correct
29 Correct 2 ms 348 KB correct
30 Correct 14 ms 600 KB correct
31 Correct 14 ms 604 KB correct
32 Correct 14 ms 604 KB correct
33 Correct 16 ms 600 KB correct
34 Execution timed out 3048 ms 171088 KB Time limit exceeded
35 Halted 0 ms 0 KB -