QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#74032 | #5439. Meet in the Middle | japan022022 | WA | 202ms | 9292kb | C++20 | 29.9kb | 2023-01-30 13:29:28 | 2023-01-30 13:29:30 |
Judging History
answer
#line 1 "library/my_template.hpp"
#if defined(LOCAL)
#include <my_template_compiled.hpp>
#else
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pi = pair<ll, ll>;
using vi = vector<ll>;
using u32 = unsigned int;
using u64 = unsigned long long;
using i128 = __int128;
template <class T>
using vc = vector<T>;
template <class T>
using vvc = vector<vc<T>>;
template <class T>
using vvvc = vector<vvc<T>>;
template <class T>
using vvvvc = vector<vvvc<T>>;
template <class T>
using vvvvvc = vector<vvvvc<T>>;
template <class T>
using pq = priority_queue<T>;
template <class T>
using pqg = priority_queue<T, vector<T>, greater<T>>;
#define vv(type, name, h, ...) \
vector<vector<type>> name(h, vector<type>(__VA_ARGS__))
#define vvv(type, name, h, w, ...) \
vector<vector<vector<type>>> name( \
h, vector<vector<type>>(w, vector<type>(__VA_ARGS__)))
#define vvvv(type, name, a, b, c, ...) \
vector<vector<vector<vector<type>>>> name( \
a, vector<vector<vector<type>>>( \
b, vector<vector<type>>(c, vector<type>(__VA_ARGS__))))
// https://trap.jp/post/1224/
#define FOR1(a) for (ll _ = 0; _ < ll(a); ++_)
#define FOR2(i, a) for (ll i = 0; i < ll(a); ++i)
#define FOR3(i, a, b) for (ll i = a; i < ll(b); ++i)
#define FOR4(i, a, b, c) for (ll i = a; i < ll(b); i += (c))
#define FOR1_R(a) for (ll i = (a)-1; i >= ll(0); --i)
#define FOR2_R(i, a) for (ll i = (a)-1; i >= ll(0); --i)
#define FOR3_R(i, a, b) for (ll i = (b)-1; i >= ll(a); --i)
#define overload4(a, b, c, d, e, ...) e
#define overload3(a, b, c, d, ...) d
#define FOR(...) overload4(__VA_ARGS__, FOR4, FOR3, FOR2, FOR1)(__VA_ARGS__)
#define FOR_R(...) overload3(__VA_ARGS__, FOR3_R, FOR2_R, FOR1_R)(__VA_ARGS__)
#define FOR_subset(t, s) \
for (ll t = (s); t >= 0; t = (t == 0 ? -1 : (t - 1) & (s)))
#define all(x) x.begin(), x.end()
#define len(x) ll(x.size())
#define elif else if
#define eb emplace_back
#define mp make_pair
#define mt make_tuple
#define fi first
#define se second
#define stoi stoll
int popcnt(int x) { return __builtin_popcount(x); }
int popcnt(u32 x) { return __builtin_popcount(x); }
int popcnt(ll x) { return __builtin_popcountll(x); }
int popcnt(u64 x) { return __builtin_popcountll(x); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 1, 2)
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(u32 x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int topbit(u64 x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
// (0, 1, 2, 3, 4) -> (-1, 0, 1, 0, 2)
int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(u32 x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
int lowbit(u64 x) { return (x == 0 ? -1 : __builtin_ctzll(x)); }
template <typename T, typename U>
T ceil(T x, U y) {
return (x > 0 ? (x + y - 1) / y : x / y);
}
template <typename T, typename U>
T floor(T x, U y) {
return (x > 0 ? x / y : (x - y + 1) / y);
}
template <typename T, typename U>
pair<T, T> divmod(T x, U y) {
T q = floor(x, y);
return {q, x - q * y};
}
template <typename T, typename U>
T SUM(const vector<U> &A) {
T sum = 0;
for (auto &&a: A) sum += a;
return sum;
}
#define MIN(v) *min_element(all(v))
#define MAX(v) *max_element(all(v))
#define LB(c, x) distance((c).begin(), lower_bound(all(c), (x)))
#define UB(c, x) distance((c).begin(), upper_bound(all(c), (x)))
#define UNIQUE(x) \
sort(all(x)), x.erase(unique(all(x)), x.end()), x.shrink_to_fit()
template <typename T>
T POP(deque<T> &que) {
T a = que.front();
que.pop_front();
return a;
}
template <typename T>
T POP(pq<T> &que) {
T a = que.top();
que.pop();
return a;
}
template <typename T>
T POP(pqg<T> &que) {
assert(!que.empty());
T a = que.top();
que.pop();
return a;
}
template <typename T>
T POP(vc<T> &que) {
assert(!que.empty());
T a = que.back();
que.pop_back();
return a;
}
template <typename F>
ll binary_search(F check, ll ok, ll ng) {
assert(check(ok));
while (abs(ok - ng) > 1) {
auto x = (ng + ok) / 2;
tie(ok, ng) = (check(x) ? mp(x, ng) : mp(ok, x));
}
return ok;
}
template <typename F>
double binary_search_real(F check, double ok, double ng, int iter = 100) {
FOR(iter) {
double x = (ok + ng) / 2;
tie(ok, ng) = (check(x) ? mp(x, ng) : mp(ok, x));
}
return (ok + ng) / 2;
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
return (a > b ? a = b, 1 : 0);
}
// ? は -1
vc<int> s_to_vi(const string &S, char first_char) {
vc<int> A(S.size());
FOR(i, S.size()) { A[i] = (S[i] != '?' ? S[i] - first_char : -1); }
return A;
}
template <typename T, typename U>
vector<T> cumsum(vector<U> &A, int off = 1) {
int N = A.size();
vector<T> B(N + 1);
FOR(i, N) { B[i + 1] = B[i] + A[i]; }
if (off == 0) B.erase(B.begin());
return B;
}
// stable sort
template <typename T>
vector<int> argsort(const vector<T> &A) {
vector<int> ids(len(A));
iota(all(ids), 0);
sort(all(ids),
[&](int i, int j) { return (A[i] == A[j] ? i < j : A[i] < A[j]); });
return ids;
}
// A[I[0]], A[I[1]], ...
template <typename T>
vc<T> rearrange(const vc<T> &A, const vc<int> &I) {
vc<T> B(len(I));
FOR(i, len(I)) B[i] = A[I[i]];
return B;
}
#endif
#line 1 "library/other/io.hpp"
// based on yosupo's fastio
#include <unistd.h>
namespace fastio {
#define FASTIO
// クラスが read(), print() を持っているかを判定するメタ関数
struct has_write_impl {
template <class T>
static auto check(T &&x) -> decltype(x.write(), std::true_type{});
template <class T>
static auto check(...) -> std::false_type;
};
template <class T>
class has_write : public decltype(has_write_impl::check<T>(std::declval<T>())) {
};
struct has_read_impl {
template <class T>
static auto check(T &&x) -> decltype(x.read(), std::true_type{});
template <class T>
static auto check(...) -> std::false_type;
};
template <class T>
class has_read : public decltype(has_read_impl::check<T>(std::declval<T>())) {};
struct Scanner {
FILE *fp;
char line[(1 << 15) + 1];
size_t st = 0, ed = 0;
void reread() {
memmove(line, line + st, ed - st);
ed -= st;
st = 0;
ed += fread(line + ed, 1, (1 << 15) - ed, fp);
line[ed] = '\0';
}
bool succ() {
while (true) {
if (st == ed) {
reread();
if (st == ed) return false;
}
while (st != ed && isspace(line[st])) st++;
if (st != ed) break;
}
if (ed - st <= 50) {
bool sep = false;
for (size_t i = st; i < ed; i++) {
if (isspace(line[i])) {
sep = true;
break;
}
}
if (!sep) reread();
}
return true;
}
template <class T, enable_if_t<is_same<T, string>::value, int> = 0>
bool read_single(T &ref) {
if (!succ()) return false;
while (true) {
size_t sz = 0;
while (st + sz < ed && !isspace(line[st + sz])) sz++;
ref.append(line + st, sz);
st += sz;
if (!sz || st != ed) break;
reread();
}
return true;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
bool read_single(T &ref) {
if (!succ()) return false;
bool neg = false;
if (line[st] == '-') {
neg = true;
st++;
}
ref = T(0);
while (isdigit(line[st])) { ref = 10 * ref + (line[st++] & 0xf); }
if (neg) ref = -ref;
return true;
}
template <typename T,
typename enable_if<has_read<T>::value>::type * = nullptr>
inline bool read_single(T &x) {
x.read();
return true;
}
bool read_single(double &ref) {
string s;
if (!read_single(s)) return false;
ref = std::stod(s);
return true;
}
bool read_single(char &ref) {
string s;
if (!read_single(s) || s.size() != 1) return false;
ref = s[0];
return true;
}
template <class T>
bool read_single(vector<T> &ref) {
for (auto &d: ref) {
if (!read_single(d)) return false;
}
return true;
}
template <class T, class U>
bool read_single(pair<T, U> &p) {
return (read_single(p.first) && read_single(p.second));
}
template <size_t N = 0, typename T>
void read_single_tuple(T &t) {
if constexpr (N < std::tuple_size<T>::value) {
auto &x = std::get<N>(t);
read_single(x);
read_single_tuple<N + 1>(t);
}
}
template <class... T>
bool read_single(tuple<T...> &tpl) {
read_single_tuple(tpl);
return true;
}
void read() {}
template <class H, class... T>
void read(H &h, T &... t) {
bool f = read_single(h);
assert(f);
read(t...);
}
Scanner(FILE *fp) : fp(fp) {}
};
struct Printer {
Printer(FILE *_fp) : fp(_fp) {}
~Printer() { flush(); }
static constexpr size_t SIZE = 1 << 15;
FILE *fp;
char line[SIZE], small[50];
size_t pos = 0;
void flush() {
fwrite(line, 1, pos, fp);
pos = 0;
}
void write(const char val) {
if (pos == SIZE) flush();
line[pos++] = val;
}
template <class T, enable_if_t<is_integral<T>::value, int> = 0>
void write(T val) {
if (pos > (1 << 15) - 50) flush();
if (val == 0) {
write('0');
return;
}
if (val < 0) {
write('-');
val = -val; // todo min
}
size_t len = 0;
while (val) {
small[len++] = char(0x30 | (val % 10));
val /= 10;
}
for (size_t i = 0; i < len; i++) { line[pos + i] = small[len - 1 - i]; }
pos += len;
}
void write(const string s) {
for (char c: s) write(c);
}
void write(const char *s) {
size_t len = strlen(s);
for (size_t i = 0; i < len; i++) write(s[i]);
}
void write(const double x) {
ostringstream oss;
oss << fixed << setprecision(15) << x;
string s = oss.str();
write(s);
}
void write(const long double x) {
ostringstream oss;
oss << fixed << setprecision(15) << x;
string s = oss.str();
write(s);
}
template <typename T,
typename enable_if<has_write<T>::value>::type * = nullptr>
inline void write(T x) {
x.write();
}
template <class T>
void write(const vector<T> val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) write(' ');
write(val[i]);
}
}
template <class T, class U>
void write(const pair<T, U> val) {
write(val.first);
write(' ');
write(val.second);
}
template <size_t N = 0, typename T>
void write_tuple(const T t) {
if constexpr (N < std::tuple_size<T>::value) {
if constexpr (N > 0) { write(' '); }
const auto x = std::get<N>(t);
write(x);
write_tuple<N + 1>(t);
}
}
template <class... T>
bool write(tuple<T...> tpl) {
write_tuple(tpl);
return true;
}
template <class T, size_t S>
void write(const array<T, S> val) {
auto n = val.size();
for (size_t i = 0; i < n; i++) {
if (i) write(' ');
write(val[i]);
}
}
void write(i128 val) {
string s;
bool negative = 0;
if (val < 0) {
negative = 1;
val = -val;
}
while (val) {
s += '0' + int(val % 10);
val /= 10;
}
if (negative) s += "-";
reverse(all(s));
if (len(s) == 0) s = "0";
write(s);
}
};
Scanner scanner = Scanner(stdin);
Printer printer = Printer(stdout);
void flush() { printer.flush(); }
void print() { printer.write('\n'); }
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
printer.write(head);
if (sizeof...(Tail)) printer.write(' ');
print(forward<Tail>(tail)...);
}
void read() {}
template <class Head, class... Tail>
void read(Head &head, Tail &... tail) {
scanner.read(head);
read(tail...);
}
} // namespace fastio
using fastio::print;
using fastio::flush;
using fastio::read;
#define INT(...) \
int __VA_ARGS__; \
read(__VA_ARGS__)
#define LL(...) \
ll __VA_ARGS__; \
read(__VA_ARGS__)
#define STR(...) \
string __VA_ARGS__; \
read(__VA_ARGS__)
#define CHAR(...) \
char __VA_ARGS__; \
read(__VA_ARGS__)
#define DBL(...) \
double __VA_ARGS__; \
read(__VA_ARGS__)
#define VEC(type, name, size) \
vector<type> name(size); \
read(name)
#define VV(type, name, h, w) \
vector<vector<type>> name(h, vector<type>(w)); \
read(name)
void YES(bool t = 1) { print(t ? "YES" : "NO"); }
void NO(bool t = 1) { YES(!t); }
void Yes(bool t = 1) { print(t ? "Yes" : "No"); }
void No(bool t = 1) { Yes(!t); }
void yes(bool t = 1) { print(t ? "yes" : "no"); }
void no(bool t = 1) { yes(!t); }
#line 2 "library/graph/base.hpp"
template <typename T>
struct Edge {
int frm, to;
T cost;
int id;
};
template <typename T = int, bool directed = false>
struct Graph {
int N, M;
using cost_type = T;
using edge_type = Edge<T>;
vector<edge_type> edges;
vector<int> indptr;
vector<edge_type> csr_edges;
vc<int> vc_deg, vc_indeg, vc_outdeg;
bool prepared;
class OutgoingEdges {
public:
OutgoingEdges(const Graph* G, int l, int r) : G(G), l(l), r(r) {}
const edge_type* begin() const {
if (l == r) { return 0; }
return &G->csr_edges[l];
}
const edge_type* end() const {
if (l == r) { return 0; }
return &G->csr_edges[r];
}
private:
const Graph* G;
int l, r;
};
bool is_prepared() { return prepared; }
constexpr bool is_directed() { return directed; }
Graph() : N(0), M(0), prepared(0) {}
Graph(int N) : N(N), M(0), prepared(0) {}
void resize(int n) { N = n; }
void add(int frm, int to, T cost = 1, int i = -1) {
assert(!prepared);
assert(0 <= frm && 0 <= to && to < N);
if (i == -1) i = M;
auto e = edge_type({frm, to, cost, i});
edges.eb(e);
++M;
}
// wt, off
void read_tree(bool wt = false, int off = 1) { read_graph(N - 1, wt, off); }
void read_graph(int M, bool wt = false, int off = 1) {
for (int m = 0; m < M; ++m) {
INT(a, b);
a -= off, b -= off;
if (!wt) {
add(a, b);
} else {
T c;
read(c);
add(a, b, c);
}
}
build();
}
void read_parent(int off = 1) {
for (int v = 1; v < N; ++v) {
INT(p);
p -= off;
add(p, v);
}
build();
}
void build() {
assert(!prepared);
prepared = true;
indptr.assign(N + 1, 0);
for (auto&& e: edges) {
indptr[e.frm + 1]++;
if (!directed) indptr[e.to + 1]++;
}
for (int v = 0; v < N; ++v) { indptr[v + 1] += indptr[v]; }
auto counter = indptr;
csr_edges.resize(indptr.back() + 1);
for (auto&& e: edges) {
csr_edges[counter[e.frm]++] = e;
if (!directed)
csr_edges[counter[e.to]++] = edge_type({e.to, e.frm, e.cost, e.id});
}
}
OutgoingEdges operator[](int v) const {
assert(prepared);
return {this, indptr[v], indptr[v + 1]};
}
vc<int> deg_array() {
if (vc_deg.empty()) calc_deg();
return vc_deg;
}
pair<vc<int>, vc<int>> deg_array_inout() {
if (vc_indeg.empty()) calc_deg_inout();
return {vc_indeg, vc_outdeg};
}
int deg(int v) {
if (vc_deg.empty()) calc_deg();
return vc_deg[v];
}
int in_deg(int v) {
if (vc_indeg.empty()) calc_deg_inout();
return vc_indeg[v];
}
int out_deg(int v) {
if (vc_outdeg.empty()) calc_deg_inout();
return vc_outdeg[v];
}
void debug() {
print("Graph");
if (!prepared) {
print("frm to cost id");
for (auto&& e: edges) print(e.frm, e.to, e.cost, e.id);
} else {
print("indptr", indptr);
print("frm to cost id");
FOR(v, N) for (auto&& e: (*this)[v]) print(e.frm, e.to, e.cost, e.id);
}
}
private:
void calc_deg() {
assert(vc_deg.empty());
vc_deg.resize(N);
for (auto&& e: edges) vc_deg[e.frm]++, vc_deg[e.to]++;
}
void calc_deg_inout() {
assert(vc_indeg.empty());
vc_indeg.resize(N);
vc_outdeg.resize(N);
for (auto&& e: edges) { vc_indeg[e.to]++, vc_outdeg[e.frm]++; }
}
};
#line 3 "library/graph/tree.hpp"
// HLD euler tour をとっていろいろ。
// 木以外、非連結でも dfs 順序や親がとれる。
template <typename GT>
struct Tree {
using Graph_type = GT;
GT &G;
using WT = typename GT::cost_type;
int N;
bool hld;
vector<int> LID, RID, head, V, parent;
vc<int> depth;
vc<WT> depth_weighted;
Tree(GT &G, int r = -1, bool hld = 1)
: G(G),
N(G.N),
hld(hld),
LID(G.N),
RID(G.N),
head(G.N, r),
V(G.N),
parent(G.N, -1),
depth(G.N, -1),
depth_weighted(G.N, 0) {
assert(G.is_prepared());
int t1 = 0;
if (r != -1) {
dfs_sz(r, -1);
dfs_hld(r, t1);
} else {
for (int r = 0; r < N; ++r) {
if (parent[r] == -1) {
head[r] = r;
dfs_sz(r, -1);
dfs_hld(r, t1);
}
}
}
}
void dfs_sz(int v, int p) {
auto &sz = RID;
parent[v] = p;
depth[v] = (p == -1 ? 0 : depth[p] + 1);
sz[v] = 1;
int l = G.indptr[v], r = G.indptr[v + 1];
auto &csr = G.csr_edges;
// 使う辺があれば先頭にする
for (int i = r - 2; i >= l; --i) {
if (hld && depth[csr[i + 1].to] == -1) swap(csr[i], csr[i + 1]);
}
int hld_sz = 0;
for (int i = l; i < r; ++i) {
auto e = csr[i];
if (depth[e.to] != -1) continue;
depth_weighted[e.to] = depth_weighted[v] + e.cost;
dfs_sz(e.to, v);
sz[v] += sz[e.to];
if (hld && chmax(hld_sz, sz[e.to]) && l < i) { swap(csr[l], csr[i]); }
}
}
void dfs_hld(int v, int ×) {
LID[v] = times++;
RID[v] += LID[v];
V[LID[v]] = v;
bool heavy = true;
for (auto &&e: G[v]) {
if (depth[e.to] <= depth[v]) continue;
head[e.to] = (heavy ? head[v] : e.to);
heavy = false;
dfs_hld(e.to, times);
}
}
vc<int> heavy_path_at(int v) {
vc<int> P = {v};
while (1) {
int a = P.back();
for (auto &&e: G[a]) {
if (e.to != parent[a] && head[e.to] == v) {
P.eb(e.to);
break;
}
}
if (P.back() == a) break;
}
return P;
}
int e_to_v(int eid) {
auto e = G.edges[eid];
return (parent[e.frm] == e.to ? e.frm : e.to);
}
int ELID(int v) { return 2 * LID[v] - depth[v]; }
int ERID(int v) { return 2 * RID[v] - depth[v] - 1; }
/* k: 0-indexed */
int LA(int v, int k) {
assert(k <= depth[v]);
while (1) {
int u = head[v];
if (LID[v] - k >= LID[u]) return V[LID[v] - k];
k -= LID[v] - LID[u] + 1;
v = parent[u];
}
}
int LCA(int u, int v) {
for (;; v = parent[head[v]]) {
if (LID[u] > LID[v]) swap(u, v);
if (head[u] == head[v]) return u;
}
}
int lca(int u, int v) { return LCA(u, v); }
int la(int u, int v) { return LA(u, v); }
int subtree_size(int v) { return RID[v] - LID[v]; }
int dist(int a, int b) {
int c = LCA(a, b);
return depth[a] + depth[b] - 2 * depth[c];
}
WT dist(int a, int b, bool weighted) {
assert(weighted);
int c = LCA(a, b);
return depth_weighted[a] + depth_weighted[b] - WT(2) * depth_weighted[c];
}
// a is in b
bool in_subtree(int a, int b) { return LID[b] <= LID[a] && LID[a] < RID[b]; }
int jump(int a, int b, ll k) {
if (k == 1) {
if (a == b) return -1;
return (in_subtree(b, a) ? LA(b, depth[b] - depth[a] - 1) : parent[a]);
}
int c = LCA(a, b);
int d_ac = depth[a] - depth[c];
int d_bc = depth[b] - depth[c];
if (k > d_ac + d_bc) return -1;
if (k <= d_ac) return LA(a, k);
return LA(b, d_ac + d_bc - k);
}
vc<int> collect_child(int v) {
vc<int> res;
for (auto &&e: G[v])
if (e.to != parent[v]) res.eb(e.to);
return res;
}
vc<pair<int, int>> get_path_decomposition(int u, int v, bool edge) {
// [始点, 終点] の"閉"区間列。
vc<pair<int, int>> up, down;
while (1) {
if (head[u] == head[v]) break;
if (LID[u] < LID[v]) {
down.eb(LID[head[v]], LID[v]);
v = parent[head[v]];
} else {
up.eb(LID[u], LID[head[u]]);
u = parent[head[u]];
}
}
if (LID[u] < LID[v]) down.eb(LID[u] + edge, LID[v]);
elif (LID[v] + edge <= LID[u]) up.eb(LID[u], LID[v] + edge);
reverse(all(down));
up.insert(up.end(), all(down));
return up;
}
vc<int> restore_path(int u, int v) {
vc<int> P;
for (auto &&[a, b]: get_path_decomposition(u, v, 0)) {
if (a <= b) {
FOR(i, a, b + 1) P.eb(V[i]);
} else {
FOR_R(i, b, a + 1) P.eb(V[i]);
}
}
return P;
}
};
#line 2 "library/graph/centroid.hpp"
template <typename GT>
vc<int> find_centroids(GT& G) {
int N = G.N;
vc<int> par(N, -1);
vc<int> V(N);
vc<int> sz(N);
int l = 0, r = 0;
V[r++] = 0;
while (l < r) {
int v = V[l++];
for (auto&& e: G[v])
if (e.to != par[v]) {
par[e.to] = v;
V[r++] = e.to;
}
}
FOR_R(i, N) {
int v = V[i];
sz[v] += 1;
int p = par[v];
if (p != -1) sz[p] += sz[v];
}
int M = N / 2;
auto check = [&](int v) -> bool {
if (N - sz[v] > M) return false;
for (auto&& e: G[v]) {
if (e.to != par[v] && sz[e.to] > M) return false;
}
return true;
};
vc<int> ANS;
FOR(v, N) if (check(v)) ANS.eb(v);
return ANS;
}
template <typename GT>
struct Centroid_Decomposition {
using edge_type = typename GT::edge_type;
GT& G;
int N;
vc<int> sz;
vc<int> par;
vector<int> cdep; // depth in centroid tree
bool calculated;
Centroid_Decomposition(GT& G)
: G(G), N(G.N), sz(G.N), par(G.N), cdep(G.N, -1) {
calculated = 0;
build();
}
private:
int find(int v) {
vc<int> V = {v};
par[v] = -1;
int p = 0;
while (p < len(V)) {
int v = V[p++];
sz[v] = 0;
for (auto&& e: G[v]) {
if (e.to == par[v] || cdep[e.to] != -1) continue;
par[e.to] = v;
V.eb(e.to);
}
}
while (len(V)) {
int v = V.back();
V.pop_back();
sz[v] += 1;
if (p - sz[v] <= p / 2) return v;
sz[par[v]] += sz[v];
}
return -1;
}
void build() {
assert(G.is_prepared());
assert(!G.is_directed());
assert(!calculated);
calculated = 1;
vc<pair<int, int>> st;
st.eb(0, 0);
while (!st.empty()) {
auto [lv, v] = st.back();
st.pop_back();
auto c = find(v);
cdep[c] = lv;
for (auto&& e: G[c]) {
if (cdep[e.to] == -1) { st.eb(lv + 1, e.to); }
}
}
}
public:
/*
root を重心とする木において、(v, path data v) の vector
を、方向ごとに集めて返す ・0 番目:root からのパスすべて(root を含む)
・i番目:i 番目の方向
f: E x edge -> E
*/
template <typename E, typename F>
vc<vc<pair<int, E>>> collect(int root, E root_val, F f) {
vc<vc<pair<int, E>>> res = {{{root, root_val}}};
for (auto&& e: G[root]) {
int nxt = e.to;
if (cdep[nxt] < cdep[root]) continue;
vc<pair<int, E>> dat;
int p = 0;
dat.eb(nxt, f(root_val, e));
par[nxt] = root;
while (p < len(dat)) {
auto [v, val] = dat[p++];
for (auto&& e: G[v]) {
if (e.to == par[v]) continue;
if (cdep[e.to] < cdep[root]) continue;
par[e.to] = v;
dat.eb(e.to, f(val, e));
}
}
res.eb(dat);
res[0].insert(res[0].end(), all(dat));
}
return res;
}
vc<vc<pair<int, int>>> collect_dist(int root) {
auto f = [&](int x, auto e) -> int { return x + 1; };
return collect(root, 0, f);
}
// (V, H), V[i] は、H における頂点 i の G における番号
// 頂点は EulerTour 順に並ぶ、V は sort されているとは限らない
pair<vc<int>, Graph<typename GT::cost_type, true>> get_subgraph(int root) {
static vc<int> conv;
while (len(conv) < N) conv.eb(-1);
vc<int> V;
using cost_type = typename GT::cost_type;
vc<tuple<int, int, cost_type>> edges;
auto dfs = [&](auto& dfs, int v, int p) -> void {
conv[v] = len(V);
V.eb(v);
for (auto&& e: G[v]) {
int to = e.to;
if (to == p) continue;
if (cdep[to] < cdep[root]) continue;
dfs(dfs, to, v);
edges.eb(conv[v], conv[to], e.cost);
}
};
dfs(dfs, root, -1);
int n = len(V);
Graph<typename GT::cost_type, true> H(n);
for (auto&& [a, b, c]: edges) H.add(a, b, c);
H.build();
for (auto&& v: V) conv[v] = -1;
return {V, H};
}
};
#line 1 "library/graph/compress_tree.hpp"
// (圧縮された木の頂点ラベルたち、グラフ)
template <typename TREE>
pair<vc<int>, typename TREE::Graph_type> compress_tree(TREE& tree, vc<int> V) {
// 大事な点をリストアップする
// もともとの根は含まれるようにする
sort(all(V), [&](auto& x, auto& y) { return tree.LID[x] < tree.LID[y]; });
int n = len(V);
FOR(i, n) {
int j = (i + 1 == n ? 0 : i + 1);
V.eb(tree.lca(V[i], V[j]));
}
V.eb(tree.V[0]);
sort(all(V), [&](auto& x, auto& y) { return tree.LID[x] < tree.LID[y]; });
V.erase(unique(all(V)), V.end());
// 辺を張ってグラフを作る
n = len(V);
using GT = typename TREE::Graph_type;
using WT = typename GT::cost_type;
GT G(n);
vc<int> st = {0};
FOR(i, 1, n) {
while (1) {
int p = V[st.back()];
int v = V[i];
if (tree.in_subtree(v, p)) break;
st.pop_back();
}
int p = V[st.back()];
int v = V[i];
WT d = tree.depth_weighted[v] - tree.depth_weighted[p];
G.add(st.back(), i, d);
st.eb(i);
}
G.build();
return {V, G};
}
#line 6 "main.cpp"
void solve() {
LL(N, Q);
Graph<ll, 0> G1(N), G2(N);
G1.read_tree(1);
G2.read_tree(1);
Tree<decltype(G2)> tree2(G2);
vvc<pair<int, int>> query_at_A(N);
FOR(q, Q) {
LL(a, b);
--a, --b;
query_at_A[a].eb(q, b);
}
vi ANS(Q);
Centroid_Decomposition<decltype(G1)> CD(G1);
vc<bool> IN2(N);
vc<int> new_idx_1(N, -1);
vc<int> new_idx_2(N, -1);
FOR(root, N) {
auto [V1, H] = CD.get_subgraph(root);
FOR(i, len(V1)) new_idx_1[V1[i]] = i;
// (方向, 距離)
vc<pair<int, ll>> dat(len(V1));
auto dfs = [&](auto& dfs, int v, int p) -> void {
for (auto&& e: H[v]) {
dat[e.to].fi = dat[v].fi;
dat[e.to].se = dat[v].se + e.cost;
dfs(dfs, e.to, v);
}
};
for (auto&& e: H[0]) {
dat[e.to].fi = e.to;
dat[e.to].se = e.cost;
dfs(dfs, e.to, 0);
}
vc<int> V2;
auto add_V2 = [&](int v) -> void {
if (IN2[v]) return;
IN2[v] = 1;
V2.eb(v);
};
FOR(i, len(V1)) {
auto a = V1[i];
add_V2(a);
for (auto&& [qid, b]: query_at_A[a]) { add_V2(b); }
}
// V2 で圧縮木を作る
auto [V, G] = compress_tree<decltype(tree2)>(tree2, V2);
FOR(i, len(V)) new_idx_2[V[i]] = i;
// 全方位をやめる
// 直径 bfs の変種で
vc<int> que(G.N);
auto bfs = [&](int s) -> vi {
vi dist(G.N, -1);
if (s == -1) return dist;
int l = 0, r = 0;
auto add = [&](int v, ll d) -> void { dist[v] = d, que[r++] = v; };
add(s, 0);
while (l < r) {
int v = que[l++];
for (auto&& e: G[v]) {
if (dist[e.to] == -1) add(e.to, dist[v] + e.cost);
}
}
return dist;
};
auto find_max2 = [&](vi& dist) -> pair<int, int> {
if (dist[0] == -1) return {-1, -1};
// 種類、点、距離
using T = tuple<int, int, ll>;
T x = {-1, -1, -1}, y = {-1, -1, -1};
FOR(v, len(dist)) {
int i = new_idx_1[V[v]];
if (i == -1) continue;
T p = {dat[i].fi, v, dist[v] + dat[i].se};
if (get<2>(x) < get<2>(p)) {
if (get<0>(x) == get<0>(p)) {
x = p;
} else {
swap(x, y);
x = p;
}
}
elif (get<2>(y) < get<2>(p)) { y = p; }
}
return {get<1>(x), get<1>(y)};
};
// 適宜 unique してよい
auto D0 = bfs(0);
auto [A, B] = find_max2(D0);
auto DA = bfs(A);
auto DB = bfs(B);
auto [C, D] = find_max2(DA);
if (C == A || C == B) C = -1;
if (D == A || D == B || D == C) D = -1;
auto [E, F] = find_max2(DB);
if (E == A || E == B || E == C || E == D) E = -1;
if (F == A || F == B || F == C || F == D || F == E) F = -1;
auto DC = bfs(C);
auto DD = bfs(D);
auto DE = bfs(E);
auto DF = bfs(F);
auto solve_query = [&](int qid, int b, int dir, ll dist) -> void {
b = new_idx_2[b];
auto upd = [&](int A, vi& DA) -> void {
if (A == -1) return;
auto [dir_A, dist_A] = dat[new_idx_1[V[A]]];
if (dir != 0 && dir_A != 0 && dir == dir_A) return;
chmax(ANS[qid], dist + DA[b] + dist_A);
};
upd(A, DA);
upd(B, DB);
upd(C, DC);
upd(D, DD);
upd(E, DE);
upd(F, DF);
};
FOR(i, len(V1)) {
auto a = V1[i];
for (auto&& [qid, b]: query_at_A[a]) {
solve_query(qid, b, dat[i].fi, dat[i].se);
}
}
// reset
for (auto&& v: V) {
IN2[v] = 0;
new_idx_1[v] = new_idx_2[v] = -1;
}
}
for (auto&& x: ANS) print(x);
}
signed main() {
solve();
return 0;
}
Details
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 2ms
memory: 3588kb
input:
3 4 1 2 1 2 3 2 1 2 2 2 3 1 1 1 1 2 2 1 2 2
output:
6 4 5 3
result:
ok 4 number(s): "6 4 5 3"
Test #2:
score: 0
Accepted
time: 2ms
memory: 3568kb
input:
2 1 1 2 1 1 2 1 1 1
output:
2
result:
ok 1 number(s): "2"
Test #3:
score: 0
Accepted
time: 2ms
memory: 3564kb
input:
2 1 1 2 1 1 2 1 1 2
output:
1
result:
ok 1 number(s): "1"
Test #4:
score: -100
Wrong Answer
time: 202ms
memory: 9292kb
input:
10000 50000 8101 5996 108427744 5996 7605 870838849 5996 5599 603303696 8101 3006 339377417 8101 6463 442516687 6463 5560 109174079 5560 4063 127596224 3006 1682 947915262 5996 1986 130416311 6463 5455 279771516 6463 2634 516688796 4063 3034 217886863 7605 5092 742375061 5599 2266 193804402 5092 140...
output:
647838384844 626539793176 514273941704 637066393138 472546379596 645842915960 484680393314 573604504956 644081575470 803875451466 556790337996 734764046916 484808162984 503723741059 529324130224 446396295431 401084222163 506499701142 438737144454 726811438160 480403616673 666761991962 701575393972 6...
result:
wrong answer 7th numbers differ - expected: '641537859258', found: '484680393314'