oj.uz

Submission #1080558

# Submission time Handle Problem Language Result Execution time Memory
1080558 2024-08-29T10:55:46 Z Elias Simurgh (IOI17_simurgh) C++17
51 / 100
 637 ms 3164 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;

unordered_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(unordered_set<int> &edges)
{
}

bool dfs_cycle(int i, int p, vector<vector<pair<int, int>>> &adj, vector<int> &vis, unordered_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))
		{
			edges.insert(j);
			return true;
		}
	}
	return false;
}

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

vector<vector<pair<int, int>>> build_adj(unordered_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;

	unordered_set<int> edges;
	unordered_set<int> fancy_edges;

	vector<int> visited(n);

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

	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);

		unordered_set<int> cycle_edges;

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

		cycle_edges.erase(i);

		unordered_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)
			{ // better than other edge
				trash_edges.insert(edge);

				fancy_edges.insert(i);
				edges.insert(i);
				action_stayed = 1;

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

				edges.insert(edge);
				fancy_edges.insert(edge);
				break;
			}
			else
			{
				if (trash_edges.count(edge))
				{
					trash_edges.insert(i);
					edges.insert(i);

					action_stayed = -1;
					break;
				}
				else
				{
					edges.insert(edge);
					stayed.insert(edge);
				}
			}
		}

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

	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 'std::vector<int> find_roads(int, std::vector<int>, std::vector<int>)':
simurgh.cpp:100:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  100 |  for (int i = 0; i < U.size(); i++)
      |                  ~~^~~~~~~~~~
simurgh.cpp:108:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  108 |  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 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 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 0 ms 348 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 1 ms 348 KB correct
13 Correct 0 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 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 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 0 ms 348 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 1 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 7 ms 344 KB correct
15 Correct 5 ms 348 KB correct
16 Correct 5 ms 348 KB correct
17 Correct 9 ms 348 KB correct
18 Correct 2 ms 436 KB correct
19 Correct 6 ms 488 KB correct
20 Correct 5 ms 348 KB correct
21 Correct 5 ms 348 KB correct
22 Correct 3 ms 348 KB correct
23 Correct 3 ms 344 KB correct
24 Correct 2 ms 348 KB correct
25 Correct 0 ms 348 KB correct
26 Correct 2 ms 432 KB correct
27 Correct 3 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 600 KB correct
30 Correct 3 ms 348 KB correct
31 Correct 3 ms 436 KB correct
32 Correct 3 ms 348 KB correct
33 Correct 2 ms 344 KB correct

Subtask #3
21.0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 348 KB correct
2 Correct 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 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 0 ms 348 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 1 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 7 ms 344 KB correct
15 Correct 5 ms 348 KB correct
16 Correct 5 ms 348 KB correct
17 Correct 9 ms 348 KB correct
18 Correct 2 ms 436 KB correct
19 Correct 6 ms 488 KB correct
20 Correct 5 ms 348 KB correct
21 Correct 5 ms 348 KB correct
22 Correct 3 ms 348 KB correct
23 Correct 3 ms 344 KB correct
24 Correct 2 ms 348 KB correct
25 Correct 0 ms 348 KB correct
26 Correct 2 ms 432 KB correct
27 Correct 3 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 600 KB correct
30 Correct 3 ms 348 KB correct
31 Correct 3 ms 436 KB correct
32 Correct 3 ms 348 KB correct
33 Correct 2 ms 344 KB correct
34 Correct 637 ms 2784 KB correct
35 Correct 580 ms 2480 KB correct
36 Correct 378 ms 1608 KB correct
37 Correct 20 ms 344 KB correct
38 Correct 597 ms 2332 KB correct
39 Correct 499 ms 2244 KB correct
40 Correct 345 ms 1700 KB correct
41 Correct 491 ms 2460 KB correct
42 Correct 494 ms 2472 KB correct
43 Correct 225 ms 1620 KB correct
44 Correct 162 ms 1364 KB correct
45 Correct 204 ms 1364 KB correct
46 Correct 159 ms 1188 KB correct
47 Correct 73 ms 600 KB correct
48 Correct 4 ms 344 KB correct
49 Correct 18 ms 552 KB correct
50 Correct 64 ms 604 KB correct
51 Correct 206 ms 1360 KB correct
52 Correct 181 ms 1616 KB correct
53 Correct 155 ms 1108 KB correct
54 Correct 233 ms 1508 KB correct
55 Correct 240 ms 1360 KB correct
56 Correct 253 ms 1364 KB correct
57 Correct 246 ms 1444 KB correct

Subtask #4
0 / 19.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 600 KB correct
2 Correct 1 ms 344 KB correct
3 Incorrect 445 ms 3164 KB WA in grader: NO
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 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 1 ms 348 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 0 ms 348 KB correct
9 Correct 1 ms 348 KB correct
10 Correct 0 ms 348 KB correct
11 Correct 1 ms 344 KB correct
12 Correct 1 ms 348 KB correct
13 Correct 0 ms 348 KB correct
14 Correct 7 ms 344 KB correct
15 Correct 5 ms 348 KB correct
16 Correct 5 ms 348 KB correct
17 Correct 9 ms 348 KB correct
18 Correct 2 ms 436 KB correct
19 Correct 6 ms 488 KB correct
20 Correct 5 ms 348 KB correct
21 Correct 5 ms 348 KB correct
22 Correct 3 ms 348 KB correct
23 Correct 3 ms 344 KB correct
24 Correct 2 ms 348 KB correct
25 Correct 0 ms 348 KB correct
26 Correct 2 ms 432 KB correct
27 Correct 3 ms 348 KB correct
28 Correct 1 ms 348 KB correct
29 Correct 1 ms 600 KB correct
30 Correct 3 ms 348 KB correct
31 Correct 3 ms 436 KB correct
32 Correct 3 ms 348 KB correct
33 Correct 2 ms 344 KB correct
34 Correct 637 ms 2784 KB correct
35 Correct 580 ms 2480 KB correct
36 Correct 378 ms 1608 KB correct
37 Correct 20 ms 344 KB correct
38 Correct 597 ms 2332 KB correct
39 Correct 499 ms 2244 KB correct
40 Correct 345 ms 1700 KB correct
41 Correct 491 ms 2460 KB correct
42 Correct 494 ms 2472 KB correct
43 Correct 225 ms 1620 KB correct
44 Correct 162 ms 1364 KB correct
45 Correct 204 ms 1364 KB correct
46 Correct 159 ms 1188 KB correct
47 Correct 73 ms 600 KB correct
48 Correct 4 ms 344 KB correct
49 Correct 18 ms 552 KB correct
50 Correct 64 ms 604 KB correct
51 Correct 206 ms 1360 KB correct
52 Correct 181 ms 1616 KB correct
53 Correct 155 ms 1108 KB correct
54 Correct 233 ms 1508 KB correct
55 Correct 240 ms 1360 KB correct
56 Correct 253 ms 1364 KB correct
57 Correct 246 ms 1444 KB correct
58 Correct 1 ms 600 KB correct
59 Correct 1 ms 344 KB correct
60 Incorrect 445 ms 3164 KB WA in grader: NO
61 Halted 0 ms 0 KB -