#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define fr first
#define sc second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)((x).size())
#define pb push_back
#define vec vector
#define endl '\n'
#pragma GCC optimize ("Ofast")
#pragma GCC optimize ("unroll-loops")
using namespace std;
using namespace __gnu_pbds;
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;
template <typename T> inline bool umin (T &a, const T &b) { if (a > b) { a = b; return 1; } return 0; }
template <typename T> inline bool umax (T &a, const T &b) { if (a < b) { a = b; return 1; } return 0; }
template <typename T>
using oset = tree<T, null_type, less <T>, rb_tree_tag, tree_order_statistics_node_update>;
const int N = 5e5 + 10;
vec <int> g[N];
int up[N][20], tin[N], tout[N], tim = 0;
int d[N];
inline void dfs (int v, int p) {
tin[v] = tim++;
up[v][0] = p;
for (int i = 1; i < 20; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
for (auto u : g[v]) {
if (u != p) {
d[u] = d[v] + 1;
dfs(u, v);
}
}
tout[v] = tim++;
}
inline is (int a, int b) { return tin[a] <= tin[b] && tout[a] >= tout[b]; }
inline int lca (int a, int b) {
if (is(a, b)) return a;
if (is(b, a)) return b;
for (int i = 19; ~i; --i) if (!is(up[a][i], b)) a = up[a][i];
return up[a][0];
}
inline dis (int a, int b) { return d[a] + d[b] - 2 * d[lca(a, b)]; }
inline void solve () {
int n, k; cin >> n >> k;
for (int i = 1; i < n; ++i) {
int u, v; cin >> u >> v; --u, --v;
g[u].pb(v); g[v].pb(u);
}
dfs(0, 0);
vec <int> a (k);
for (auto &i : a) cin >> i, --i;
queue <int> q;
vec <int> dist (n, -1);
for (auto i : a) {
q.push(i);
dist[i] = 0;
}
while (sz(q)) {
int v = q.front(); q.pop();
for (auto u : g[v]) {
if (!~dist[u]) {
dist[u] = dist[v] + 1;
q.push(u);
}
}
}
set <tuple <int, int, vec <int>>> urugvai;
for (int i = 0; i < n; ++i) {
int cnt = 0;
vec <int> sis;
for (int j = 0; j < k; ++j) {
if (dis(i, a[j]) == dist[i]) {
++cnt;
sis.pb(j);
}
}
urugvai.insert({cnt, i, sis});
}
vec <bool> used (k);
vec <int> ans;
while (true) {
pair <int, tuple <int, int, vec <int>>> mx = {-1, {0, 0, {}}};
for (auto [_, v, sis] : urugvai) {
int cnt = 0;
for (auto i : sis) cnt += !used[i];
umax(mx, {cnt, {_, v, sis}});
}
if (mx.fr < 1) break;
for (auto i : get<2>(mx.sc)) used[i] = 1;
ans.pb(get<1>(mx.sc));
urugvai.erase(mx.sc);
}
cout << sz(ans) << endl;
for (auto i : ans) cout << i + 1 << " ";
}
signed main () {
ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#ifdef LOCAL
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif // LOCAL
int t = 1; //cin >> t;
while (t--) solve();
return 0;
}
Compilation message
pastiri.cpp:47:8: error: ISO C++ forbids declaration of 'is' with no type [-fpermissive]
47 | inline is (int a, int b) { return tin[a] <= tin[b] && tout[a] >= tout[b]; }
| ^~
pastiri.cpp:54:8: error: ISO C++ forbids declaration of 'dis' with no type [-fpermissive]
54 | inline dis (int a, int b) { return d[a] + d[b] - 2 * d[lca(a, b)]; }
| ^~~
