제출 #874387

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
874387		Hamed_Ghaffari	Pipes (CEOI15_pipes)	C++17	0 / 100	852 ms	65536 KiB

pipes

#include <bits/stdc++.h>
using namespace std;

typedef long long       ll;
typedef pair<int, int>  pii;

#define FastIO          cin.tie(NULL); cout.tie(NULL); ios_base::sync_with_stdio(false);
#define FileIO          freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout);
#define F               first
#define S               second
#define max_heap(T)     priority_queue<T>
#define min_heap(T)     priority_queue<T, vector<T>, greater<T>>
#define fr(i,a,b)       for(int i=a;i<b;i++)
#define frr(i,a,b)      for(int i=a;i>b;i--)
#define frin(i,A)       for(auto &i : A)
#define frp(a,b,A)      for(auto [a, b] : A)
#define SZ(x)           (int)x.size()
#define all(A)          A.begin(), A.end()
#define mins(a,b)       a = min(a,b)
#define maxs(a,b)       a = max(a,b)
#define pb              push_back
#define kill(x)         cout << x << '\n', exit(0)
#define md(a)           (a%MOD+MOD)%MOD

const ll  INF  = 2e9;
const ll  MOD  = 1e9 + 7;
const int MAXN = 1e5 + 5;
const int LOG  = 30;

int n, m, par[MAXN][2], hi[MAXN];
vector<int> g[MAXN];

void DSU() {
	fr(i, 1, n+1)
		par[i][0] = par[i][1] = i;
}
int Find(int v, int x) { return v == par[v][x] ? v : par[v][x] = Find(par[v][x], x); }
void Union(int u, int v) {
	if(Find(u, 0) != Find(v, 0)) {
		par[Find(u, 0)][0] = Find(v, 0);
		g[u].pb(v);
		g[v].pb(u);
		return;
	}
	if(Find(u, 1) != Find(v, 1)) {
		par[Find(u, 1)][1] = Find(v, 1);
		g[u].pb(v);
		g[v].pb(u);
		return;
	}
}

int dfs(int v, int p) {
	hi[v] = hi[p]+1;
	int res = 0;
	frin(u, g[v])
		if(u == p)
			continue;
		else if(!hi[u])
			res += dfs(u, v);
		else if(hi[u] < hi[v])
			res++;
		else
			res--;
	if(v != p && res == 0)
		cout << v << ' ' << p << '\n';
	return res;
}

void solve() {
	cin >> n >> m;
	DSU();
	int u, v;
	while(m--) {
		cin >> u >> v;
		Union(u, v);
	}
	fr(i, 1, n+1)
		if(!hi[i])
			dfs(i, i);
}

int32_t main() {
	FastIO
	int T = 1;
	// cin >> T;
	while(T--)
		solve();
	return 0;
}

• Subtask 1: 0 / 10
• Subtask 2: 0 / 10
• Subtask 3: 0 / 10
• Subtask 4: 0 / 10
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• Subtask 10: 0 / 10