結果
| 問題 |
No.1212 Second Path
|
| コンテスト | |
| ユーザー |
 haruki_K
|
| 提出日時 | 2020-08-30 15:55:02 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
TLE
|
| 実行時間 | - |
| コード長 | 11,724 bytes |
| コンパイル時間 | 3,253 ms |
| コンパイル使用メモリ | 227,284 KB |
| 最終ジャッジ日時 | 2025-01-13 23:13:24 |
|
ジャッジサーバーID （参考情報） |
judge4 / judge3 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 19 TLE * 26 |
ソースコード
// >>> TEMPLATES
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using i32 = int32_t;
using i64 = int64_t;
using u32 = uint32_t;
using u64 = uint64_t;
#define int ll
#define double ld
#define rep(i,n) for (int i = 0; i < (int)(n); i++)
#define rep1(i,n) for (int i = 1; i <= (int)(n); i++)
#define repR(i,n) for (int i = (int)(n)-1; i >= 0; i--)
#define rep1R(i,n) for (int i = (int)(n); i >= 1; i--)
#define loop(i,a,B) for (int i = a; i B; i++)
#define loopR(i,a,B) for (int i = a; i B; i--)
#define all(x) begin(x), end(x)
#define allR(x) rbegin(x), rend(x)
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fst first
#define snd second
template <class Int> auto constexpr inf = numeric_limits<Int>::max()/2-1;
auto constexpr INF32 = inf<int32_t>;
auto constexpr INF64 = inf<int64_t>;
auto constexpr INF = inf<int>;
#ifdef LOCAL
#include "debug.hpp"
#else
#define dump(...) (void)(0)
#define say(x) (void)(0)
#define debug if (0)
#endif
template <class T> using pque_max = priority_queue<T>;
template <class T> using pque_min = priority_queue<T, vector<T>, greater<T> >;
template <class T, class = typename T::iterator, class = typename enable_if<!is_same<T, string>::value>::type>
ostream& operator<<(ostream& os, T const& v) { bool f = true; for (auto const& x : v) os << (f ? "" : " ") << x, f = false; return os; }
template <class T, class = typename T::iterator, class = typename enable_if<!is_same<T, string>::value>::type>
istream& operator>>(istream& is, T &v) { for (auto& x : v) is >> x; return is; }
template <class T, class S> ostream& operator<<(ostream& os, pair<T,S> const& p) { return os << "(" << p.first << ", " << p.second << ")"; }
template <class T, class S> istream& operator>>(istream& is, pair<T,S>& p) { return is >> p.first >> p.second; }
struct IOSetup { IOSetup() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(15); } } iosetup;
template <class F> struct FixPoint : private F {
constexpr FixPoint(F&& f) : F(forward<F>(f)) {}
template <class... T> constexpr auto operator()(T&&... x) const { return F::operator()(*this, forward<T>(x)...); }
};
struct MakeFixPoint {
template <class F> constexpr auto operator|(F&& f) const { return FixPoint<F>(forward<F>(f)); }
};
#define MFP MakeFixPoint()|
#define def(name, ...) auto name = MFP [&](auto &&name, __VA_ARGS__)
template <class T, size_t d> struct vec_impl {
using type = vector<typename vec_impl<T,d-1>::type>;
template <class... U> static type make_v(size_t n, U&&... x) { return type(n, vec_impl<T,d-1>::make_v(forward<U>(x)...)); }
};
template <class T> struct vec_impl<T,0> { using type = T; static type make_v(T const& x = {}) { return x; } };
template <class T, size_t d = 1> using vec = typename vec_impl<T,d>::type;
template <class T, size_t d = 1, class... Args> auto make_v(Args&&... args) { return vec_impl<T,d>::make_v(forward<Args>(args)...); }
template <class T> void quit(T const& x) { cout << x << endl; exit(0); }
template <class T, class U> constexpr bool chmin(T& x, U const& y) { if (x > y) { x = y; return true; } return false; }
template <class T, class U> constexpr bool chmax(T& x, U const& y) { if (x < y) { x = y; return true; } return false; }
template <class It> constexpr auto sumof(It b, It e) { return accumulate(b,e,typename iterator_traits<It>::value_type{}); }
template <class T> int sz(T const& x) { return x.size(); }
template <class C, class T> int lbd(C const& v, T const& x) {
return lower_bound(v.begin(), v.end(), x)-v.begin();
}
template <class C, class T> int ubd(C const& v, T const& x) {
return upper_bound(v.begin(), v.end(), x)-v.begin();
}
const int dx[] = { 1,0,-1,0 };
const int dy[] = { 0,1,0,-1 };
constexpr int popcnt(ll x) { return __builtin_popcountll(x); }
template <class Int> struct Random {
mt19937_64 mt{random_device{}()};
//mt19937_64 mt{(unsigned)time(0)};
Int a,b; // [a,b]
Random(Int a, Int b) : a(a), b(b) {}
Int operator()() { return uniform_int_distribution<Int>(a,b)(mt); }
};
template <class Int> Int rand(Int a, Int b) { // [a,b]
static mt19937_64 mt{random_device{}()};
return uniform_int_distribution<Int>(a,b)(mt);
}
// <<<
// >>> reord
void reord_impl(vector<int> const&) { }
template <class C, class... Args>
void reord_impl(vector<int> const& idx, C& v, Args&&... args) {
auto t = v;
rep (i,v.size()) t[i] = v[idx[i]];
swap(v,t);
reord_impl(idx, forward<Args>(args)...);
}
template <class Comp, class C, class... Args,
class = decltype(declval<Comp>()(0,0))>
void reord(Comp comp, C& v, Args&&... args) {
vector<int> idx(v.size());
iota(idx.begin(), idx.end(), 0);
sort(idx.begin(), idx.end(), comp);
reord_impl(idx, v, args...);
}
template <class C, class... Args>
void reord(C& v, Args&&... args) {
vector<int> idx(v.size());
iota(idx.begin(), idx.end(), 0);
sort(idx.begin(), idx.end(), [&](int i, int j) { return v[i] < v[j]; });
reord_impl(idx, v, args...);
}
template <class C, class... Args>
void reordR(C& v, Args&&... args) {
vector<int> idx(v.size());
iota(idx.begin(), idx.end(), 0);
sort(idx.begin(), idx.end(), [&](int i, int j) { return v[i] > v[j]; });
reord_impl(idx, v, args...);
}
// <<<
// >>> HLD
struct HLD {
vector<vector<int32_t>> g;
vector<int32_t> vid,inv,head,sz,dep,par;
bool built = false;
HLD(int n) : g(n),vid(n),inv(n),head(n),sz(n,1),dep(n,0),par(n,-1) {}
vector<int32_t> const& operator[](int i) const {
assert(built);
assert(0 <= i); assert(i < (int)g.size());
return g[i];
}
void add_edge(int x, int y) {
g[x].push_back(y);
g[y].push_back(x);
built = false;
}
void build(int root = 0) {
dfs1(root);
head[root] = root;
int id = 0;
dfs2(root,id);
rep (x,g.size()) inv[vid[x]] = x;
built = true;
}
int lca(int x, int y) const {
assert(built);
while (1) {
if (vid[x] > vid[y]) swap(x,y);
if (head[x] == head[y]) return x;
y = par[head[y]];
}
}
int dist(int x, int y) const {
assert(built);
return dep[x] + dep[y] - 2*dep[lca(x,y)];
}
int edge_id(int x, int y) const {
assert(built);
if (x == par[y]) return vid[y];
if (y == par[x]) return vid[x];
return -1;
}
vector<pair<int,int>> path(int x, int y, bool with_lca) const {
assert(built);
vector<pair<int,int>> ret;
while (1) {
if (vid[x] > vid[y]) swap(x,y);
if (head[x] == head[y]) {
ret.emplace_back(vid[x] + (with_lca ? 0 : 1), vid[y]+1);
return ret;
} else {
ret.emplace_back(vid[head[y]], vid[y]+1);
y = par[head[y]];
}
}
}
vector<pair<int,int>> vertices(int x, int y) const {
return path(x,y,true);
}
vector<pair<int,int>> edges(int x, int y) const {
return path(x,y,false);
}
void dfs1(int x) {
for (auto &y : g[x]) {
if (y == par[x]) {
swap(y, g[x].back());
g[x].pop_back();
break;
}
}
for (auto &y : g[x]) {
par[y] = x;
dep[y] = dep[x] + 1;
dfs1(y);
sz[x] += sz[y];
if (sz[y] > sz[g[x][0]]) swap(y, g[x][0]);
}
}
void dfs2(int x, int &id) {
vid[x] = id++;
for (auto y : g[x]) {
head[y] = (y == g[x][0] ? head[x] : y);
dfs2(y,id);
}
}
};
// <<<
// >>> segment tree
template <class Handler>
struct Segtree : Handler {
using Value = typename Handler::Value;
using Handler::unit; // () -> Value
using Handler::merge; // (Value,Value) -> Value
vector<Value> v; // use v[1..2*cap-1]
int cap; // // capacity: power of 2
int n; // original size
Segtree() {}
template <class... T> Segtree(T&&... x) { init(forward<T>(x)...); }
template <class F, class = decltype(declval<F>()(0))>
void init(int n, F gen) {
assert(n >= 0); this->n = n;
cap = n; //for (cap = 1; cap < n; cap <<= 1) ;;
v.resize(2*cap, unit());
for (int i = 0; i < n; i++) v[cap+i] = gen(i);
for (int i = cap-1; i >= 1; i--) v[i] = merge(v[2*i],v[2*i+1]);
}
void init(int n) { init(n, [&](int) { return unit(); }); }
void init(int n, Value const& x) { init(n, [&](int) { return x; }); }
void init(vector<Value> const& v) { init(v.size(), [&](int i) { return v[i]; }); }
int size() const { return n; }
void set(int i, Value const& x) {
assert(0 <= i); assert(i < size());
i += cap; v[i] = x;
while (i > 1) i >>= 1, v[i] = merge(v[2*i],v[2*i+1]);
}
Value operator[](int i) const { return get(i); }
Value get(int i) const {
assert(0 <= i); assert(i < size());
return v[cap + i];
}
// [l,r)
Value get(int l, int r) const {
assert(0 <= l); assert(l <= r); assert(r <= size());
Value x = unit(), y = unit();
for (l += cap, r += cap; l < r; l >>= 1, r >>= 1) {
if (l&1) x = merge(x, v[l++]);
if (r&1) y = merge(v[--r], y);
}
return merge(x,y);
}
vector<Value> dat() const {
vector<Value> ret(size());
for (int i = 0; i < size(); i++) ret[i] = get(i);
return ret;
}
};
// <<<
struct RangeXor {
using Value = u64;
constexpr static Value unit() { return 0; }
constexpr static Value merge(Value x, Value y) { return x^y; }
};
int32_t main() {
int n; cin >> n;
HLD g(n);
vector<int> a(n-1),b(n-1),w(n-1);
rep (i,n-1) {
cin >> a[i] >> b[i] >> w[i], --a[i],--b[i];
g.add_edge(a[i],b[i]);
}
g.build();
reord(w,a,b);
dump(g.vid);
dump(a);
dump(b);
dump(w);
vector<int> weight(n);
rep (i,n-1) {
int id = g.edge_id(a[i],b[i]);
weight[id] = w[i];
}
vector<int> dep(n);
def (dfs, int x, int d) -> void {
dep[x] = d;
for (int y : g[x]) {
int id = g.edge_id(x,y);
dfs(y,d+weight[id]);
}
};
dfs(0,0);
dump(dep);
int q; cin >> q;
vector<int> x(q),y(q);
rep (i,q) cin >> x[i] >> y[i], --x[i],--y[i];
vector<int> l(q,0),r(q,INF);
while (true) {
// dump(l,r);
map<int,vector<int>> z;
rep (i,q) {
if (l[i]+1 < r[i]) {
int mid = (l[i]+r[i])/2;
z[mid].eb(i);
}
}
if (z.empty()) break;
Segtree<RangeXor> seg(n);
auto add = [&](int x, u64 val) {
int id = g.vid[x];
seg.set(id, seg[id]^val);
};
int idx = 0;
for (auto const& [mid,v] : z) {
while (idx < n-1 && w[idx] <= mid) {
auto val = rand(0ull,-1ull);
add(a[idx], val);
add(b[idx], val);
idx++;
}
for (int j : v) {
u64 sum = 0;
for (auto [l,r] : g.vertices(x[j],y[j])) {
sum ^= seg.get(l,r);
}
(sum > 0 ? r[j] : l[j]) = mid;
}
}
}
dump(l);
dump(r);
rep (i,q) {
if (r[i] == INF) {
cout << -1 << "\n";
} else {
int mi = r[i];
int len = dep[x[i]] + dep[y[i]] - 2*dep[g.lca(x[i],y[i])];
dump(i,x[i],y[i],mi,len);
cout << len + mi*2 << "\n";
}
}
}