Submission #1265416

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265416		escobrand	Pipes (CEOI15_pipes)	C++20	80 / 100	560 ms	19936 KiB

pipes

#include <bits/stdc++.h>

using namespace std;
#define all(v) v.begin(),v.end()
#define pb push_back
#define ll long long
#define ld long double
#define fi first
#define se second
#define mk make_pair
typedef pair<int,int> pii;

const int maxn = 1e5 + 10;
int i,n,t,m,low[maxn],tim[maxn],u,v;
vector<int> adj[maxn];

struct DSU
{
  int p[maxn];
  
  DSU(int n)
  {
    for(int i = 1;i<=n;i++)p[i] = i;
  }
  
  int fi(int i)
  {
    while(i != p[i])i = p[i] = p[p[i]];
    return i;
  }
  
  bool unite(int u,int v)
  {
    u = fi(u);
    v = fi(v);
    if(u == v)return 0;
    p[v] = u;
    return 1;
  }
};

void dfs(int i,int pa)
{
  tim[i] = low[i] = ++t;
  bool ch = 0;
  for(const int &k : adj[i])
  {
    if(k == pa && !ch)
    {
      ch = 1;
      continue;
    }
    if(tim[k])low[i] = min(low[i],tim[k]);
    else 
    {
      dfs(k,i);
      low[i] = min(low[i],low[k]);
      if(low[k] == tim[k])cout<<i<<' '<<k<<'\n';
    }
  }
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    
    cin>>n>>m;
    DSU a(n),b(n);
    while(m--)
    {
      cin>>u>>v;
      if(a.unite(u,v) || b.unite(u,v))
      {
        adj[u].pb(v);
        adj[v].pb(u);
      }
    }
    for(i = 1;i<=n;i++)
    {
      if(!tim[i])
      {
        dfs(i,0);
      }
    }
    
    
    return 0;
}

• 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: 0 / 10
• Subtask 9: 0 / 10
• Subtask 10: 10 / 10