Submission #1172924

#	Time	Username	Problem	Language	Result	Execution time	Memory
1172924		jill	Senior Postmen (BOI14_postmen)	C++20	100 / 100	321 ms	87988 KiB

postmen

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define pb push_back
#define eb emplace_back
#define se second
typedef long long ll;
using pii = pair<int, int>;
const int nmax = 1e6 + 5;
vector<pii> adj[nmax];
vector<int> path;
int deg[nmax], vis[nmax], n, m;
void dfs(int u) {
  while (!adj[u].empty()) {
    auto [son, idx] = adj[u].back();
    adj[u].pop_back();
    if (vis[idx])
      continue;
    vis[idx] = 1;
    dfs(son);
  }
  path.pb(u);
  deg[u]++;
  if (deg[u] == 2) {
    cout << u << ' ';
    path.pop_back();
    while (path.back() != u) {
      cout << path.back() << ' ';
      deg[path.back()]--;
      path.pop_back();
    }
    cout << '\n';
    deg[u] = 1;
  }
}
signed main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  cout.tie(0);
  cin >> n >> m;
  for (int u, v, i = 1; i <= m; i++) {
    cin >> u >> v;
    adj[u].pb({v, i});
    adj[v].pb({u, i});
  }
  dfs(1);
}

• Subtask 1: 38 / 38
• Subtask 2: 17 / 17
• Subtask 3: 45 / 45