Submission #527244

#	Time	Username	Problem	Language	Result	Execution time	Memory
527244		siewjh	Pipes (CEOI15_pipes)	C++17	10 / 100	832 ms	36276 KiB

pipes

#include <iostream>
#include <vector>
#include <algorithm>
#include <climits>
#include <set>
using namespace std;
const int MAXN = 4005;
vector<int> adjlist[MAXN];
int tvis[MAXN], lo[MAXN];
int cnt = 0;
set<pair<int, int>> ans;
void dfs(int x, int par) {
	tvis[x] = lo[x] = cnt++;
	for (auto nxt : adjlist[x]) {
		if (nxt == par) continue;
		if (tvis[nxt] != INT_MAX) lo[x] = min(lo[x], tvis[nxt]);
		else {
			dfs(nxt, x);
			lo[x] = min(lo[x], lo[nxt]);
			if (lo[nxt] > tvis[x]) ans.insert({ min(nxt, x), max(nxt, x) });
		}
	}
}
int main() {
	ios_base::sync_with_stdio(false);
	cin.tie(0); cout.tie(0);
	int nodes, edges; cin >> nodes >> edges;
	set<pair<int, int>> elist, mult;
	for (int i = 0; i < edges; i++) {
		int a, b; cin >> a >> b;
		if (a > b) swap(a, b);
		adjlist[a].push_back(b);
		adjlist[b].push_back(a);
		if (elist.count({ a, b })) mult.insert({ a, b });
		elist.insert({ a, b });
	}
	for (int i = 1; i <= nodes; i++) tvis[i] = INT_MAX;
	for (int i = 1; i <= nodes; i++) 
		if (tvis[i] == INT_MAX)
			dfs(i, -1);
	for (auto x : ans) 
		if (!mult.count(x))
			cout << x.first << ' ' << x.second << '\n';
	return 0;
}

• Subtask 1: 10 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
• Subtask 5: 0 / 10
• Subtask 6: 0 / 10
• Subtask 7: 0 / 10
• Subtask 8: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 0 / 10