Submission #380060

#	Time	Username	Problem	Language	Result	Execution time	Memory
380060		Return_0	Pipes (CEOI15_pipes)	C++17	100 / 100	1361 ms	12396 KiB

pipes

// #pragma GCC optimize("Ofast,unroll-loops")
// #pragma comment(linker, "/stack:200000000")
// #pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,fma,tune=native")

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

typedef int ll;
typedef long double ld;
typedef pair <ll, ll> pll;

#ifdef SINA
#define dbg(...) __f(#__VA_ARGS__, __VA_ARGS__)
template <typename Arg1> void __f(const char* name, Arg1&& arg1) { cout << name << " : " << arg1 << std::endl; }
template <typename Arg1, typename... Args> void __f (const char* names, Arg1&& arg1, Args&&... args) {
	const char* comma = strchr(names + 1, ',');cout.write(names, comma - names) << " : " << arg1<<" | ";__f(comma+1, args...); }
#define dbg2(x, j, n) cout<< #x << " : "; output((j), (n), x, 1); cout.flush();
#else
#define dbg(...) 0
#define dbg2(x, j, n) 0
#endif
#define SZ(x) ((ll)((x).size()))
#define File(s, t) freopen(s ".txt", "r", stdin); freopen(t ".txt", "w", stdout);
#define input(j, n, a) for (int _i = (j); _i < (n)+(j); _i++) cin>> a[_i];
#define output(j, n, a, t) for (int _i = (j); _i < (n)+(j); _i++) cout<< a[_i] << (((t) && _i != (n)+(j)-1)? ' ' : '\n');
#define kill(x) return cout<< (x) << endl, 0
#define cl const ll
#define fr first
#define sc second
#define lc (v << 1)
#define rc (lc | 1)
#define mid ((l + r) >> 1)
#define All(x) (x).begin(), (x).end()

cl inf = sizeof(ll) == 4 ? (1e9 + 10) : (3e18), mod = 1e9 + 7, MOD = 998244353;

template <class A,class B> ostream& operator << (ostream& out,const pair<A,B>&a){return out<<'('<<a.first<<", "<<a.second<<')';}
template <class A> ostream& operator << (ostream& out, const vector<A> &a) {
	out<< '['; for (int i = -1; ++i < int(a.size());) out<< a[i] << (i + 1 < int(a.size()) ? ", " : ""); return out<<']'; }
template <class T, typename _t = less <T> > using Tree = tree <T, null_type, _t, rb_tree_tag, tree_order_statistics_node_update>;

cl N = 1e5 + 1;

ll cut_candidate [N], _2ecc [N], n, m;
vector <ll> adj [N];
bitset <N> bt;

ll root (ll par [], cl &v) {
	if (!par[v]) return v;
	return par[v] = root(par, par[v]);
}

inline bool unite (ll par [], ll v, ll u) {
	v = root(par, v); u = root(par, u);
	if (v == u) return false;
	par[u] = v;
	return true;
}

void dfs (cl &v, cl &pr = 0) {
	_2ecc[v] = _2ecc[pr] + 1;
	cut_candidate[v] = _2ecc[v];
	for (auto &u : adj[v]) {
		if (u == pr) {
			if (bt[v]) cut_candidate[v] = min(cut_candidate[v], _2ecc[u]);
			bt[v] = 1;
		} else if (_2ecc[u]) cut_candidate[v] = min(cut_candidate[v], _2ecc[u]);
		else dfs(u, v), cut_candidate[v] = min(cut_candidate[v], cut_candidate[u]);
	}
	if (pr && cut_candidate[v] == _2ecc[v]) cout<< pr << ' ' << v << '\n';
}

int main ()
{
	ios::sync_with_stdio(false); cin.tie(0); cout.tie(0);

	cin>> n >> m; ll w = 0;
	for (ll i = 0, v, u; i < m; i++) {
		cin>> v >> u;
		if (unite(cut_candidate, v, u)) {
			adj[v].push_back(u); /* adj[v].shrink_to_fit(); */
			adj[u].push_back(v); /* adj[u].shrink_to_fit(); */
			w++;
		} else if (unite(_2ecc, v, u)) {
			adj[v].push_back(u); /* adj[v].shrink_to_fit(); */
			adj[u].push_back(v); /* adj[u].shrink_to_fit(); */
		}
	}

	memset(_2ecc, 0, sizeof _2ecc);
	for (ll v = 1; v <= n; v++) if (!_2ecc[v]) dfs(v);
  
	return 0;
}
/*
10 11
1 7
1 8
1 6
2 8
6 7
5 8
2 5
2 3
2 4
3 4
10 9

*/

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