제출 #1096686

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1096686		nguyenvu	Railway (BOI17_railway)	C++14	0 / 100	44 ms	23624 KiB

railway

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

int n,m,k;
vector<int> a[500007];
map<pair<int,int>,int> mp;
int d[500007];

namespace sub1 {
  bool check() {
    return 1;
  }

  bool f[500007];
  vector<pair<int,int>> res;

  int dfs(int i) {
    f[i] = 1;

    bool ok = (d[i]>=k);
    for (const int &j : a[i]) {
      if (f[j]) continue;
      if (dfs(j)) {
        res.push_back(pair<int,int>(min(i,j),max(i,j)));
        ok = 1;
      }
    }

    return ok;
  }

  void solve() {
    for (int i=1; i<=n; i++) {
      if (f[i]) continue;
      if (d[i] < k) continue;
      dfs(i);
    }

    for (pair<int,int> &i : res) {
      i.first = mp[i];
    }
    sort(res.begin(),res.end());

    cout << res.size() << '\n';
    for (const pair<int,int> &i : res) cout << i.first << ' ';
  }
}

int main() {

  ios_base::sync_with_stdio(0);
  cin.tie(0); cout.tie(0);

  cin >> n >> m >> k;
  for (int i=1; i<n; i++) {
    int u,v;
    cin >> u >> v;

    a[u].push_back(v);
    a[v].push_back(u);

    mp[pair<int,int>(min(u,v),max(u,v))] = i;
  }
  for (int i=1; i<=n; i++) {
    sort(a[i].begin(),a[i].end());
  }

  for (int i=1; i<=m; i++) {
    int x;
    cin >> x;

    while (x--) {
      int t;
      cin >> t;

      d[t]++;
    }
  }

  if (sub1::check()) {
    sub1::solve();
    return 0;
  }

  return 0;
}

• Subtask 1: 0 / 8
• Subtask 2: 0 / 15
• Subtask 3: 0 / 7
• Subtask 4: 0 / 29
• Subtask 5: 0 / 16
• Subtask 6: 0 / 25