oj.uz

답안 #1080429

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
1080429 2024-08-29T09:51:11 Z Elias Simurgh (IOI17_simurgh) C++17
30 / 100
 1542 ms 2932 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;
}

int cnt_common_set(set<int> &a)
{
	return 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);
		}
		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)
		wrong_answer();

	return _count_common_roads_internal(r);
}

int main()
{
	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");

	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:115:20: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  115 |  for (int i = 0; i < u.size(); i++)
      |                  ~~^~~~~~~~~~

Subtask #1
13.0 / 13.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 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 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 344 KB correct

Subtask #2
17.0 / 17.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 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 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 344 KB correct
14 Correct 39 ms 848 KB correct
15 Correct 33 ms 344 KB correct
16 Correct 34 ms 348 KB correct
17 Correct 23 ms 344 KB correct
18 Correct 5 ms 348 KB correct
19 Correct 25 ms 348 KB correct
20 Correct 22 ms 348 KB correct
21 Correct 25 ms 348 KB correct
22 Correct 13 ms 344 KB correct
23 Correct 11 ms 344 KB correct
24 Correct 10 ms 344 KB correct
25 Correct 1 ms 344 KB correct
26 Correct 10 ms 348 KB correct
27 Correct 11 ms 348 KB correct
28 Correct 3 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 11 ms 468 KB correct
31 Correct 11 ms 348 KB correct
32 Correct 11 ms 348 KB correct
33 Correct 11 ms 464 KB correct

Subtask #3
0 / 21.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 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 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 344 KB correct
14 Correct 39 ms 848 KB correct
15 Correct 33 ms 344 KB correct
16 Correct 34 ms 348 KB correct
17 Correct 23 ms 344 KB correct
18 Correct 5 ms 348 KB correct
19 Correct 25 ms 348 KB correct
20 Correct 22 ms 348 KB correct
21 Correct 25 ms 348 KB correct
22 Correct 13 ms 344 KB correct
23 Correct 11 ms 344 KB correct
24 Correct 10 ms 344 KB correct
25 Correct 1 ms 344 KB correct
26 Correct 10 ms 348 KB correct
27 Correct 11 ms 348 KB correct
28 Correct 3 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 11 ms 468 KB correct
31 Correct 11 ms 348 KB correct
32 Correct 11 ms 348 KB correct
33 Correct 11 ms 464 KB correct
34 Incorrect 1542 ms 1620 KB WA in grader: NO
35 Halted 0 ms 0 KB -

Subtask #4
0 / 19.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB correct
2 Correct 0 ms 348 KB correct
3 Incorrect 1262 ms 2932 KB WA in grader: NO
4 Halted 0 ms 0 KB -

Subtask #5
0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 0 ms 348 KB correct
2 Correct 1 ms 348 KB correct
3 Correct 0 ms 348 KB correct
4 Correct 0 ms 348 KB correct
5 Correct 0 ms 348 KB correct
6 Correct 1 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 0 ms 348 KB correct
12 Correct 0 ms 348 KB correct
13 Correct 0 ms 344 KB correct
14 Correct 39 ms 848 KB correct
15 Correct 33 ms 344 KB correct
16 Correct 34 ms 348 KB correct
17 Correct 23 ms 344 KB correct
18 Correct 5 ms 348 KB correct
19 Correct 25 ms 348 KB correct
20 Correct 22 ms 348 KB correct
21 Correct 25 ms 348 KB correct
22 Correct 13 ms 344 KB correct
23 Correct 11 ms 344 KB correct
24 Correct 10 ms 344 KB correct
25 Correct 1 ms 344 KB correct
26 Correct 10 ms 348 KB correct
27 Correct 11 ms 348 KB correct
28 Correct 3 ms 348 KB correct
29 Correct 1 ms 348 KB correct
30 Correct 11 ms 468 KB correct
31 Correct 11 ms 348 KB correct
32 Correct 11 ms 348 KB correct
33 Correct 11 ms 464 KB correct
34 Incorrect 1542 ms 1620 KB WA in grader: NO
35 Halted 0 ms 0 KB -