Submission #948410

#	Time	Username	Problem	Language	Result	Execution time	Memory
948410		vjudge1	Pipes (CEOI15_pipes)	C++17	0 / 100	180 ms	23388 KiB

pipes

#include <bits/stdc++.h>
using namespace std;
//#define int long long
#define all(x) x.begin(), x.end()
#define size(x) (int)x.size()

template<class S, class T>
bool chmin(S &a, const T &b) {
  return a > b ? (a = b) == b : false;
}
template<class S, class T>
bool chmax(S &a, const T &b) {
  return a < b ? (a = b) == b : false;
}
const int N = 5000;

bool r[N][N], /*us[N][N], mul[N][N],*/ vis[N];
int tin[N], fup[N], timer;
vector<pair<short, short>> bridges;

short n; int m;
 
void dfs(short v, short p = -1) {
  vis[v] = true;
  tin[v] = fup[v] = ++timer;
  for (short to = 0; to < n; ++to) {
    if (to == p || to == v || !r[v][to]) continue;
    else if (vis[to]) chmin(fup[v], tin[to]);
    else {
      dfs(to, v);
      chmin(fup[v], fup[to]);
      if (fup[to] > tin[v]) {
        bridges.push_back({v, to});
      }
    }
  }
}

signed main() {
  cin.tie(nullptr)->sync_with_stdio(false);
  cin >> n >> m;
  for (int i = 0; i < m; ++i) {
    short a, b; cin >> a >> b;
    a--, b--;
    r[a][b] = r[b][a] = true;
    //if (us[a][b]) mul[a][b] = mul[b][a] = true;
    //us[a][b] = us[b][a] = true;
  }
  for (short i = 0; i < n; ++i) {
    if (!vis[i]) dfs(i);
  }
  for (auto [a, b] : bridges) {
    //if (!mul[a][b]) {
      cout << a + 1 << ' ' << b + 1 << '\n';
    //}
  }
}

• Subtask 1: 0 / 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