oj.uz

Submission #852394

# Submission time Handle Problem Language Result Execution time Memory
852394 2023-09-21T18:14:51 Z serifefedartar Naboj (COCI22_naboj) C++17
110 / 110
 298 ms 28852 KB 
#include <bits/stdc++.h>
using namespace std;
 
#define fast ios::sync_with_stdio(0);cin.tie(0);
#define s second
#define f first
typedef long long ll;
const ll MOD = 1e9 + 7;
const ll LOGN = 20;
const ll MAXN = 2e5 + 5;

vector<vector<pair<int,int>>> graph;
int indeg[MAXN], outdeg[MAXN], vis[MAXN];
int main() {
	fast
	int n, m, a, b;
	cin >> n >> m;

	graph = vector<vector<pair<int,int>>>(n+1, vector<pair<int,int>>());
	for (int i = 0; i < m; i++) {
		cin >> a >> b;
		graph[a].push_back({b, 0});
		graph[b].push_back({a, 1});
		indeg[a]++;
		outdeg[b]++;
	}

	queue<int> q;
	for (int i = 1; i <= n; i++) {
		if (indeg[i] == 0 || outdeg[i] == 0)
			q.push(i);
	}

	stack<pair<int,int>> ans;
	while (!q.empty()) {
		int node = q.front();
		q.pop();

		if (vis[node])
			continue;
		vis[node] = true;

		int state = -1;
		for (auto u : graph[node]) {
			if (vis[u.f])
				continue;

			if (u.s == 1)
				indeg[u.f]--;
			else
				outdeg[u.f]--;

			if (indeg[u.f] == 0 || outdeg[u.f] == 0)
				q.push(u.f);
			state = u.s;
		}

		if (state != -1)
			ans.push({node, !state}); 
	}

	for (int i = 1; i <= n; i++) {
		if (!vis[i]) {
			cout << "-1\n";
			return 0;
		}
	}

	cout << ans.size() << "\n"; 
	while (!ans.empty()) {
		cout << ans.top().f << " " << ans.top().s << "\n";
		ans.pop();
	}
}

Subtask #1
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2392 KB Output is correct
3 Correct 1 ms 2392 KB Output is correct
4 Correct 1 ms 2392 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2592 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2392 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2392 KB Output is correct
13 Correct 1 ms 2392 KB Output is correct
14 Correct 0 ms 2396 KB Output is correct

Subtask #2
25.0 / 25.0

# Verdict Execution time Memory Grader output
1 Correct 107 ms 19536 KB Output is correct
2 Correct 95 ms 19268 KB Output is correct
3 Correct 40 ms 11304 KB Output is correct
4 Correct 104 ms 19120 KB Output is correct
5 Correct 91 ms 19280 KB Output is correct
6 Correct 90 ms 19104 KB Output is correct
7 Correct 89 ms 19280 KB Output is correct
8 Correct 64 ms 15444 KB Output is correct
9 Correct 88 ms 19280 KB Output is correct
10 Correct 96 ms 19124 KB Output is correct

Subtask #3
70.0 / 70.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2392 KB Output is correct
2 Correct 1 ms 2392 KB Output is correct
3 Correct 1 ms 2392 KB Output is correct
4 Correct 1 ms 2392 KB Output is correct
5 Correct 1 ms 2392 KB Output is correct
6 Correct 1 ms 2396 KB Output is correct
7 Correct 1 ms 2592 KB Output is correct
8 Correct 1 ms 2396 KB Output is correct
9 Correct 1 ms 2392 KB Output is correct
10 Correct 1 ms 2396 KB Output is correct
11 Correct 1 ms 2396 KB Output is correct
12 Correct 1 ms 2392 KB Output is correct
13 Correct 1 ms 2392 KB Output is correct
14 Correct 0 ms 2396 KB Output is correct
15 Correct 107 ms 19536 KB Output is correct
16 Correct 95 ms 19268 KB Output is correct
17 Correct 40 ms 11304 KB Output is correct
18 Correct 104 ms 19120 KB Output is correct
19 Correct 91 ms 19280 KB Output is correct
20 Correct 90 ms 19104 KB Output is correct
21 Correct 89 ms 19280 KB Output is correct
22 Correct 64 ms 15444 KB Output is correct
23 Correct 88 ms 19280 KB Output is correct
24 Correct 96 ms 19124 KB Output is correct
25 Correct 105 ms 20304 KB Output is correct
26 Correct 103 ms 20308 KB Output is correct
27 Correct 137 ms 22352 KB Output is correct
28 Correct 167 ms 25424 KB Output is correct
29 Correct 89 ms 18932 KB Output is correct
30 Correct 160 ms 24912 KB Output is correct
31 Correct 18 ms 6232 KB Output is correct
32 Correct 125 ms 20656 KB Output is correct
33 Correct 179 ms 27472 KB Output is correct
34 Correct 122 ms 20756 KB Output is correct
35 Correct 181 ms 27472 KB Output is correct
36 Correct 95 ms 20048 KB Output is correct
37 Correct 162 ms 25940 KB Output is correct
38 Correct 162 ms 23796 KB Output is correct
39 Correct 219 ms 27472 KB Output is correct
40 Correct 161 ms 24912 KB Output is correct
41 Correct 157 ms 24912 KB Output is correct
42 Correct 240 ms 28240 KB Output is correct
43 Correct 130 ms 21840 KB Output is correct
44 Correct 298 ms 28852 KB Output is correct
45 Correct 116 ms 20840 KB Output is correct
46 Correct 153 ms 25120 KB Output is correct