// author : anhtun_hi , nqg
#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll, ll>
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define reset(h, v) memset(h, v, sizeof h)
#define Forv(i, a) for(auto& i : a)
#define For(i, a, b) for(int i = a; i <= b; ++i)
#define Ford(i, a, b) for(int i = a; i >= b; --i)
#define c_bit(i) __builtin_popcountll(i)
#define Bit(mask, i) ((mask >> i) & 1LL)
#define onbit(mask, i) ((mask) bitor (1LL << i))
#define offbit(mask, i) ((mask) &~ (1LL << i))
using namespace std;
namespace std {
template <typename T, int D>
struct _vector : public vector <_vector <T, D - 1>> {
static_assert(D >= 1, "Dimension must be positive!");
template <typename... Args>
_vector(int n = 0, Args... args) : vector <_vector <T, D - 1>> (n, _vector <T, D - 1> (args...)) {}
};
template <typename T> struct _vector <T, 1> : public vector <T> {
_vector(int n = 0, const T& val = T()) : vector <T> (n, val) {}
};
template <class A, class B> bool minimize(A &a, B b){return a > b ? a = b, true : false;}
template <class A, class B> bool maximize(A &a, B b){return a < b ? a = b, true : false;}
}
const int dx[] = {0, 0, +1, -1}, dy[] = {-1, +1, 0, 0}, LOG = 20, base = 311, inf = 1e9 + 5;
const int MAXN = 1e6 + 5;
const ll mod = 1e9 + 7;
const ll oo = 1e18;
//#define int long long
int sz[MAXN], p[MAXN]; bool del[MAXN];
vector<ii> g[MAXN];
int dep[MAXN], pre[MAXN][22]; ll d[MAXN];
void dfs(int u, int par) {
pre[u][0] = par, sz[u] = 1;
For(k, 1, 20) pre[u][k] = pre[pre[u][k - 1]][k - 1];
for(auto [v, w] : g[u]) {
if (v == par) continue;
dep[v] = dep[u] + 1;
d[v] = d[u] + w;
dfs(v, u);
sz[u] += sz[v];
}
}
int getlca(int u, int v) {
if (dep[u] < dep[v]) swap(u, v);
int len = dep[u] - dep[v];
For(k, 0, 20) if (Bit(len, k)) u = pre[u][k];
if (u == v) return u;
Ford(k, 20, 0) if (pre[u][k] != pre[v][k])
u = pre[u][k], v = pre[v][k];
return pre[u][0];
}
ll dist(int u, int v){
return d[u] + d[v] - 2 * d[getlca(u, v)];
}
void dfsSize(int u, int par){
sz[u] = 1;
for(auto [v, w] : g[u]) if((v ^ par) && !del[v]){
dfsSize(v, u);
sz[u] += sz[v];
}
}
int find(int u, int par, int n){
for(auto [v, w] : g[u])if(v ^ par){
if(sz[v] > n / 2 && !del[v]) return find(v, u, n);
}
return u;
}
void buildCentroid(int u, int par){
dfsSize(u, par);
int c = find(u, par, sz[u]);
del[c] = true;
p[c] = par;
for(auto [v, _] : g[c]) if((v ^ par) && !del[v]) {
buildCentroid(v, c);
}
}
multiset<ll> res[MAXN]; bool op[MAXN];
void update(int u){
int v = u;
op[u] ^= 1;
while(v){
if(op[u]) res[v].insert({dist(u, v)});
else res[v].erase({dist(u, v)});
v = p[v];
}
if(op[u]) res[v].insert({dist(u, v)});
else res[v].erase({dist(u, v)});
}
ll get(int u){
int v = u;
ll ans = oo;
while(v){
if(res[v].size()){
auto it = res[v].begin();
minimize(ans, *it + dist(u, v));
}
v = p[v];
}
if(res[v].size()) {
auto it = res[v].begin();
minimize(ans, *it + dist(u, v));
}
return ans;
}
long long Query(int S, int X[], int T, int Y[]){
// cin >> S;
// cin >> T;
// For(i, 0, S - 1) cin >> X[i];
// For(i, 0, T - 1) cin >> Y[i];
For(i, 0, S - 1){
int u = X[i] + 1;
update(u);
}
ll ans = oo;
For(i, 0, T - 1){
minimize(ans, get(Y[i] + 1));
}
For(i, 0, S - 1){
int u = X[i] + 1;
update(u);
}
return ans;
}
int n, a[MAXN], b[MAXN], w[MAXN], S, T, x[MAXN], y[MAXN];
void Init(int n, int a[], int b[], int w[]){
// cin >> n;
// int q; cin >> q;
// For(i, 0, n - 2) {
// cin >> a[i] >> b[i] >> w[i];
// }
For(i, 0, n - 2){
++a[i], ++b[i];
g[a[i]].push_back({b[i], w[i]});
g[b[i]].push_back({a[i], w[i]});
}
dfs(1, 0);
buildCentroid(1, 0);
// while(q--){
// cout << Query(S, x, T, y) << '\n';
// }
}
void Solve() {
// int q; cin >> q;
Init(n, a, b, w);
}
int32_t main() {
cin.tie(0) -> sync_with_stdio(0);
if(fopen("JOI14_factories.inp", "r")) {
freopen("JOI14_factories.inp", "r", stdin);
freopen("JOI14_factories.out", "w", stdout);
}
int t = 1;
// cin >> t;
for (int test = 1; test <= t; test++) {
Solve();
}
return 0;
}
Compilation message
factories.cpp: In function 'int32_t main()':
factories.cpp:176:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
176 | freopen("JOI14_factories.inp", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
factories.cpp:177:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
177 | freopen("JOI14_factories.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/usr/bin/ld: /tmp/cc53JWwj.o: in function `main':
grader.cpp:(.text.startup+0x0): multiple definition of `main'; /tmp/cc6EctNj.o:factories.cpp:(.text.startup+0x0): first defined here
collect2: error: ld returned 1 exit status
