Submission #1133381

#	Time	Username	Problem	Language	Result	Execution time	Memory
1133381		Kubeti	Pipes (CEOI15_pipes)	C++20	70 / 100	609 ms	17824 KiB

pipes

#include <bits/stdc++.h>

using namespace std;

const int nmax = 1e5 + 1, mod = 1e6 + 7;

struct DSU {
  int root[nmax], sz[nmax];

  void init(int n) {
    for(int i = 1; i <= n; i++) {
      root[i] = i;
      sz[i] = 1;
    }
  }

  int find(int a) {
    if(root[a] == a) {
      return a;
    }
    return root[a] = find(root[a]);
  }

  void unite(int a, int b) {
    assert(a != b);
    if(sz[a] > sz[b]) {
      swap(a, b);
    }
    root[a] = b;
    sz[b] += sz[a];
  }
} d1, d2;

vector<pair<int, int>> adj[nmax];
int low[nmax];
int t[nmax];
bool f[nmax];
int ind, comp, timer = 0;

void dfs(int i, int timp) {
  f[i] = 1;
  t[i] = low[i] = timer++;
  for(auto curr : adj[i]) {
    int it = curr.first;
    if(curr.second == timp) {
      continue;
    }
    if(f[it]) {
      low[i] = min(low[i], t[it]);
    } else {
      dfs(it, curr.second);
      low[i] = min(low[i], low[it]);
      if(t[i] < low[it]) {
        cout << i << " " << it << '\n';
      }
    }
  }
}

int32_t main(){
  ios_base::sync_with_stdio(0);cin.tie(0);
  int n, m;
  cin >> n >> m;
  d1.init(n), d2.init(n);
  int cnt = 0;
  for(int i = 1; i <= m; i++) {
    int a, b;
    cin >> a >> b;
    if(d1.find(a) != d1.find(b)) {
      cnt++;
      d1.unite(d1.find(a), d1.find(b));
      adj[a].push_back({b, cnt});
      adj[b].push_back({a, cnt});
    } else if(d2.find(a) != d2.find(b)) {
      cnt++;
      d2.unite(d2.find(a), d2.find(b));
      adj[a].push_back({b, cnt});
      adj[b].push_back({a, cnt});
    }
  }
  assert(cnt < n * 2 + 1);
  for(int i = 1; i <= n; i++) {
    if(!f[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: 0 / 10