# | Time | Username | Problem | Language | Result | Execution time | Memory |
---|---|---|---|---|---|---|---|
387500 | saarang123 | Factories (JOI14_factories) | C++17 | 0 ms | 0 KiB |
This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
#ifndef saarang
#include "factories.h"
#endif
using namespace std;
std::mt19937 rng(15);
const int mxn = 500 * 1000 + 3, lgn = 20;
int up[mxn][lgn], d[mxn], par[mxn], sz[mxn], n, og;
long long dt[mxn], ans[mxn];
vector<array<int, 2>> g[mxn];
bool cent[mxn];
void dfs(int v, int p) {
up[v][0] = (p < 0 ? v : p);
for(auto &[u, w] : g[v]) if(u != p) {
d[u] = d[v] + 1;
dt[u] = dt[v] + w;
dfs(u, v);
}
for(int i = 1; i < lgn; i++)
up[v][i] = up[up[v][i - 1]][i - 1];
}
int kth(int v, int di) {
for(int i = 0; i < lgn; i++)
if(di >> i & 1)
v = up[v][i];
return v;
}
int lca(int a, int b) {
if(d[a] > d[b])
swap(a, b);
b = kth(b, d[b] - d[a]);
if(a == b) return a;
for(int i = lgn - 1; i >= 0; i--)
if(up[a][i] != up[b][i])
a = up[a][i], b = up[b][i];
return up[a][0];
}
long long dist(int a, int b) { return dt[a] + dt[b] - 2 * dt[lca(a, b)]; }
int dfssz(int v, int p) {
sz[v] = 1;
for(auto &[u, w] : g[v]) if(u != p && !cent[u])
sz[v] += dfssz(u, v);
return sz[v];
}
int fcent(int v, int p) {
for(auto &[u, w] : g[v]) if(u != p && !cent[u]) {
if(sz[u] > sz[og] / 2)
return fcent(u, v);
}
return v;
}
void decompose(int v, int p) {
dfssz(v, -1);
int centroid = fcent(og = v, -1);
cent[centroid] = true;
par[centroid] = p;
for(auto &[u, w] : g[centroid])
if(u != p && !cent[u])
decompose(u, centroid);
}
void Init(int N, int A[], int B[], int D[]) {
n = N;
for(int i = 0; i < n - 1; i++) {
g[A[i]].push_back({B[i], D[i]});
g[B[i]].push_back({A[i], D[i]});
}
dfs(0, -1);
decompose(0, -1);
for(int i = 0; i <= n; i++)
ans[i] = 1'000'000'000'000'000'000;
}
void upd(int v) {
for(int p = v; p != -1; p = par[p])
ans[p] = min(ans[p], dist(p, v));
}
void fix(int v) {
for(int p = v; p != -1; p = par[p])
ans[p] = ans[n];
}
long long query(int v) {
long long res = ans[n];
for(int p = v; p != -1; p = par[p])
res = min(res, ans[p] + dist(p, v));
return res;
}
long long Query(int S, int X[], int T, int Y[]) {
for(int i = 0; i < T; i++)
upd(Y[i]);
long long answer = ans[n];
for(int i = 0; i < S; i++)
answer = min(answer, query(X[i]));
for(int i = 0; i < T; i++)
fix(Y[i]);
return answer;
}
signed main() {
std::ios::sync_with_stdio(0);
std::cout.tie(0);
std::cin.tie(0);
#ifdef saarang
freopen("/home/saarang/Documents/cp/input.txt", "r", stdin);
freopen("/home/saarang/Documents/cp/output.txt", "w", stdout);
#endif
int N, Q;
cin >> N >> Q;
int A[N - 1], B[N - 1], D[N - 1];
for(int i = 0; i < N - 1; i++)
cin >> A[i] >> B[i] >> D[i];
Init(N, A, B, D);
while(Q--) {
int S, T;
cin >> S >> T;
int X[S], Y[T];
for(int i = 0; i < S; i++)
cin >> X[i];
for(int i = 0; i < T; i++)
cin >> Y[i];
cout << Query(S, X, T, Y) << '\n';
}
return 0;
}