// In the name of the God
#include <bits/stdc++.h>
#define ll long long
#define int long long
#define pb push_back
#define F first
#define S second
#define mp make_pair
#define pii pair <int, int>
#define smin(x, y) (x) = min((x), (y))
#define smax(x, y) (x) = max((x), (y))
#define all(x) (x).begin(), (x).end()
using namespace std;
const int inf = (1e9+7)*(1e9+7);
const int mod = 998244353;
const int maxn = 5e5+5;
int n, sz[maxn], mn[maxn];
bool mark[maxn];
vector <pii> adj[maxn], c[maxn];
void dfs1(int v, int p) {
sz[v] = 1;
for (pii e : adj[v]) {
int u = e.F;
if (!mark[u] and u != p) {
dfs1(u, v); sz[v] += sz[u];
}
}
}
int dfs2(int v, int s, int p) {
for (pii e : adj[v]) {
int u = e.F;
if (!mark[u] and u != p and sz[u] > s/2) return dfs2(u, s, v);
}
return v;
}
void dfs3(int v, int h, int p, int b) {
c[v].pb(mp(b, h));
for (pii e : adj[v]) {
int u = e.F;
if (!mark[u] and u != p) dfs3(u, h+e.S, v, b);
}
}
void cd(int v) {
dfs1(v, v);
v = dfs2(v, sz[v], v);
dfs3(v, 0, v, v);
mark[v] = 1;
for (pii e : adj[v]) {
int u = e.F;
if (!mark[u]) cd(u);
}
}
void Init(int N, int A[], int B[], int D[]) {
n = N;
for (int i = 0; i < n-1; i++) {
adj[A[i]].pb(mp(B[i], D[i]));
adj[B[i]].pb(mp(A[i], D[i]));
}
cd(0);
fill(mn, mn+n, inf);
}
long long Query(int S, int X[], int T, int Y[]) {
int ans = inf;
for (int i = 0; i < S; i++) {
int v = X[i];
for (pii p : c[v]) smin(mn[p.F], p.S);
}
for (int i = 0; i < T; i++) {
int v = Y[i];
for (pii p : c[v]) smin(ans, mn[p.F]+p.S);
}
for (int i = 0; i < S; i++) {
int v = X[i];
for (pii p : c[v]) mn[p.F] = inf;
}
return ans;
}
// int32_t main() {
// ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
// cin >> n >> q;
// for (int i = 0; i < n-1; i++) {
// int v, u, w; cin >> v >> u >> w;
// adj[v].pb(mp(u, w));
// adj[u].pb(mp(v, w));
// }
// cd(0);
// fill(mn, mn+n, inf);
// while (q--) {
// int s, t, ans = inf; cin >> s >> t;
// while (s--) {
// int v; cin >> v;
// for (pii p : c[v]) smin(mn[p.F], p.S);
// vec.pb(v);
// }
// while (t--) {
// int v; cin >> v;
// for (pii p : c[v]) smin(ans, mn[p.F]+p.S);
// }
// for (int v : vec) {
// for (pii p : c[v]) mn[p.F] = inf;
// }
// vec.clear();
// cout << ans << '\n';
// }
// return 0;
// }
Compilation message
/usr/bin/ld: /tmp/cc4Yx6R1.o: in function `main':
grader.cpp:(.text.startup+0x37d): undefined reference to `Init(int, int*, int*, int*)'
/usr/bin/ld: grader.cpp:(.text.startup+0x412): undefined reference to `Query(int, int*, int, int*)'
collect2: error: ld returned 1 exit status
