oj.uz

Submission #527309

# Submission time Handle Problem Language Result Execution time Memory
527309 2022-02-17T05:54:04 Z siewjh Pipes (CEOI15_pipes) C++17
100 / 100
 1053 ms 15640 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>
using namespace std;
const int MAXN = 100'005;
vector<vector<int>> adjlist;
vector<int> tvis, lo;
int cnt = 0;
void dfs(int x, int par) {
	tvis[x] = lo[x] = cnt++;
	bool vpar = 0;
	for (auto nxt : adjlist[x]) {
		if (nxt == par && !vpar) {
			vpar = 1;
			continue;
		}
		if (tvis[nxt] != -1) lo[x] = min(lo[x], tvis[nxt]);
		else {
			dfs(nxt, x);
			lo[x] = min(lo[x], lo[nxt]);
			if (lo[nxt] > tvis[x]) cout << nxt << ' ' << x << '\n';
		}
	}
}
int root(int a, vector<int>& par) {
	if (par[a] == -1) return a;
	else return par[a] = root(par[a], par);
}
void merge(int a, int b, vector<int>& par, vector<int> &rank) {
	if (rank[a] > rank[b]) swap(a, b); // b has higher rank
	par[a] = b;
	if (rank[a] == rank[b]) rank[b]++;
}
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int nodes, edges; cin >> nodes >> edges;
	vector<int> par1(nodes + 1, -1), par2(nodes + 1, -1), rank1(nodes + 1, -1), rank2(nodes + 1, -1);
	adjlist.resize(nodes + 1);
	tvis.resize(nodes + 1); lo.resize(nodes + 1);
	for (int i = 0; i < edges; i++) {
		int a, b; cin >> a >> b;
		if (root(a, par1) != root(b, par1)) {
			merge(root(a, par1), root(b, par1), par1, rank1);
			adjlist[a].push_back(b);
			adjlist[b].push_back(a);
		}
		else if (root(a, par2) != root(b, par2)) {
			merge(root(a, par2), root(b, par2), par2, rank2);
			adjlist[a].push_back(b);
			adjlist[b].push_back(a);
		}
	}
	for (int i = 1; i <= nodes; i++) tvis[i] = -1;
	for (int i = 1; i <= nodes; i++)
		if (tvis[i] == -1)
			dfs(i, -1);
	return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 936 KB Output is correct
2 Correct 3 ms 724 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 88 ms 744 KB Output is correct
2 Correct 78 ms 600 KB Output is correct

Subtask #4
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 135 ms 1688 KB Output is correct
2 Correct 165 ms 1144 KB Output is correct

Subtask #5
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 266 ms 3908 KB Output is correct
2 Correct 191 ms 3668 KB Output is correct

Subtask #6
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 379 ms 11016 KB Output is correct
2 Correct 273 ms 7164 KB Output is correct

Subtask #7
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 517 ms 12716 KB Output is correct
2 Correct 487 ms 9384 KB Output is correct

Subtask #8
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 675 ms 15628 KB Output is correct
2 Correct 658 ms 9956 KB Output is correct

Subtask #9
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 878 ms 15640 KB Output is correct
2 Correct 804 ms 10068 KB Output is correct

Subtask #10
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1053 ms 14792 KB Output is correct
2 Correct 948 ms 11816 KB Output is correct