結果
| 問題 |
No.1833 Subway Planning
|
| コンテスト | |
| ユーザー |
 yuto1115
|
| 提出日時 | 2022-02-04 22:50:14 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
TLE
|
| 実行時間 | - |
| コード長 | 10,821 bytes |
| コンパイル時間 | 2,739 ms |
| コンパイル使用メモリ | 213,588 KB |
| 最終ジャッジ日時 | 2025-01-27 19:35:33 |
|
ジャッジサーバーID （参考情報） |
judge3 / judge1 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 20 TLE * 3 |
ソースコード
#include<bits/stdc++.h>
#define overload4(_1, _2, _3, _4, name, ...) name
#define rep1(i, n) for (ll i = 0; i < ll(n); ++i)
#define rep2(i, s, n) for (ll i = ll(s); i < ll(n); ++i)
#define rep3(i, s, n, d) for(ll i = ll(s); i < ll(n); i+=d)
#define rep(...) overload4(__VA_ARGS__,rep3,rep2,rep1)(__VA_ARGS__)
#define rrep1(i, n) for (ll i = ll(n)-1; i >= 0; i--)
#define rrep2(i, n, t) for (ll i = ll(n)-1; i >= (ll)t; i--)
#define rrep3(i, n, t, d) for (ll i = ll(n)-1; i >= (ll)t; i-=d)
#define rrep(...) overload4(__VA_ARGS__,rrep3,rrep2,rrep1)(__VA_ARGS__)
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define SUM(a) accumulate(all(a),0LL)
#define MIN(a) *min_element(all(a))
#define MAX(a) *max_element(all(a))
#define SORT(a) sort(all(a));
#define REV(a) reverse(all(a));
#define SZ(a) int(a.size())
#define popcount(x) __builtin_popcountll(x)
#define pf push_front
#define pb push_back
#define ef emplace_front
#define eb emplace_back
#define ppf pop_front
#define ppb pop_back
#ifdef __LOCAL
#define debug(...) { cout << #__VA_ARGS__; cout << ": "; print(__VA_ARGS__); cout << flush; }
#else
#define debug(...) void(0);
#endif
#define INT(...) int __VA_ARGS__;scan(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__;scan(__VA_ARGS__)
#define STR(...) string __VA_ARGS__;scan(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__;scan(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__;scan(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__;scan(__VA_ARGS__)
using namespace std;
using ll = long long;
using ld = long double;
using P = pair<int, int>;
using LP = pair<ll, ll>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vd = vector<double>;
using vvd = vector<vd>;
using vs = vector<string>;
using vc = vector<char>;
using vvc = vector<vc>;
using vb = vector<bool>;
using vvb = vector<vb>;
using vp = vector<P>;
using vvp = vector<vp>;
template<class T>
using PQ = priority_queue<pair<T, int>, vector<pair<T, int>>, greater<pair<T, int>>>;
template<class S, class T>
istream &operator>>(istream &is, pair<S, T> &p) { return is >> p.first >> p.second; }
template<class S, class T>
ostream &operator<<(ostream &os, const pair<S, T> &p) { return os << '{' << p.first << ", " << p.second << '}'; }
template<class S, class T, class U>
istream &operator>>(istream &is, tuple<S, T, U> &t) { return is >> get<0>(t) >> get<1>(t) >> get<2>(t); }
template<class S, class T, class U>
ostream &operator<<(ostream &os, const tuple<S, T, U> &t) {
return os << '{' << get<0>(t) << ", " << get<1>(t) << ", " << get<2>(t) << '}';
}
template<class T>
istream &operator>>(istream &is, vector<T> &v) {
for (T &t: v) { is >> t; }
return is;
}
template<class T>
ostream &operator<<(ostream &os, const vector<T> &v) {
os << '[';
rep(i, v.size()) os << v[i] << (i == int(v.size() - 1) ? "" : ", ");
return os << ']';
}
template<class T>
ostream &operator<<(ostream &os, const deque<T> &v) {
os << '[';
rep(i, v.size()) os << v[i] << (i == int(v.size() - 1) ? "" : ", ");
return os << ']';
}
template<class T>
ostream &operator<<(ostream &os, const set<T> &st) {
os << '{';
auto it = st.begin();
while (it != st.end()) {
os << (it == st.begin() ? "" : ", ") << *it;
it++;
}
return os << '}';
}
template<class T>
ostream &operator<<(ostream &os, const multiset<T> &st) {
os << '{';
auto it = st.begin();
while (it != st.end()) {
os << (it == st.begin() ? "" : ", ") << *it;
it++;
}
return os << '}';
}
template<class T>
void vecout(const vector<T> &v, char div = '\n') {
rep(i, v.size()) cout << v[i] << (i == int(v.size() - 1) ? '\n' : div);
}
template<class T>
bool chmin(T &a, T b) {
if (a > b) {
a = b;
return true;
}
return false;
}
template<class T>
bool chmax(T &a, T b) {
if (a < b) {
a = b;
return true;
}
return false;
}
void scan() {}
template<class Head, class... Tail>
void scan(Head &head, Tail &... tail) {
cin >> head;
scan(tail...);
}
template<class T>
void print(const T &t) { cout << t << '\n'; }
template<class Head, class... Tail>
void print(const Head &head, const Tail &... tail) {
cout << head << ' ';
print(tail...);
}
template<class... T>
void fin(const T &... a) {
print(a...);
exit(0);
}
template<class T>
vector<T> &operator+=(vector<T> &v, T x) {
for (T &t: v) t += x;
return v;
}
template<class T>
vector<T> &operator-=(vector<T> &v, T x) {
for (T &t: v) t -= x;
return v;
}
template<class T>
vector<T> &operator*=(vector<T> &v, T x) {
for (T &t: v) t *= x;
return v;
}
template<class T>
vector<T> &operator/=(vector<T> &v, T x) {
for (T &t: v) t /= x;
return v;
}
struct Init_io {
Init_io() {
ios::sync_with_stdio(false);
cin.tie(nullptr);
cout.tie(nullptr);
cout << boolalpha << fixed << setprecision(15);
cerr << boolalpha << fixed << setprecision(15);
}
} init_io;
const string yes[] = {"no", "yes"};
const string Yes[] = {"No", "Yes"};
const string YES[] = {"NO", "YES"};
const int inf = 1001001001;
const ll linf = 1001001001001001001;
void rearrange(const vi &) {}
template<class T, class... Tail>
void rearrange(const vi &ord, vector<T> &head, Tail &...tail) {
assert(ord.size() == head.size());
vector<T> ori = head;
rep(i, ord.size()) head[i] = ori[ord[i]];
rearrange(ord, tail...);
}
template<class T, class... Tail>
void sort_by(vector<T> &head, Tail &... tail) {
vi ord(head.size());
iota(all(ord), 0);
sort(all(ord), [&](int i, int j) { return head[i] < head[j]; });
rearrange(ord, head, tail...);
}
template<class T, class S>
vector<T> cumsum(const vector<S> &v, bool shift_one = true) {
int n = v.size();
vector<T> res;
if (shift_one) {
res.resize(n + 1);
rep(i, n) res[i + 1] = res[i] + v[i];
} else {
res.resize(n);
if (n) {
res[0] = v[0];
rep(i, 1, n) res[i] = res[i - 1] + v[i];
}
}
return res;
}
vvi graph(int n, int m, bool directed = false, int origin = 1) {
vvi G(n);
rep(_, m) {
INT(u, v);
u -= origin, v -= origin;
G[u].pb(v);
if (!directed) G[v].pb(u);
}
return G;
}
template<class T>
vector<vector<pair<int, T>>> weighted_graph(int n, int m, bool directed = false, int origin = 1) {
vector<vector<pair<int, T>>> G(n);
rep(_, m) {
int u, v;
T w;
scan(u, v, w);
u -= origin, v -= origin;
G[u].eb(v, w);
if (!directed) G[v].eb(u, w);
}
return G;
}
template<class M>
class LCA {
using S = typename M::S;
int n;
vector<vector<pair<int, S>>> G;
vi dep;
vvi par;
vector<vector<S>> dp;
void dfs(int u, int p, S ps, int d) {
par[0][u] = p;
dep[u] = d;
dp[0][u] = ps;
for (auto[v, s]: G[u]) if (v != p) dfs(v, u, s, d + 1);
}
void init() {
n = G.size();
dep.assign(n, -1);
par.resize(30);
dp.resize(30);
rep(i, 30) {
par[i].resize(n);
dp[i].assign(n, M::e);
}
rep(i, n) if (dep[i] == -1) dfs(i, -1, M::e, 0);
rep(k, 29) rep(i, n) {
if (par[k][i] < 0) par[k + 1][i] = -1;
else {
par[k + 1][i] = par[k][par[k][i]];
dp[k + 1][i] = M::op(dp[k][i], dp[k][par[k][i]]);
}
}
}
public:
LCA(const vector<vector<pair<int, S>>> &G) : G(G) { init(); }
int operator()(int u, int v) {
if (dep[u] > dep[v]) swap(u, v);
rep(k, 30) if ((dep[v] - dep[u]) >> k & 1) v = par[k][v];
if (u == v) return u;
rrep(k, 30) {
if (par[k][u] != par[k][v]) {
u = par[k][u];
v = par[k][v];
}
}
assert(par[0][u] == par[0][v]);
return par[0][u];
}
int dist(int u, int v) {
int w = this->operator()(u, v);
return dep[u] + dep[v] - dep[w] * 2;
}
S prod(int u, int v) {
int l = this->operator()(u, v);
int du = dist(u, l), dv = dist(v, l);
S res = M::e;
rep(k, 30) {
if (du >> k & 1) {
res = M::op(res, dp[k][u]);
u = par[k][u];
}
if (dv >> k & 1) {
res = M::op(res, dp[k][v]);
v = par[k][v];
}
}
return res;
}
// path from u to v (including u, v)
vi path(int u, int v) {
int l = this->operator()(u, v);
vi ul, vl;
while (l != u) {
ul.pb(u);
u = par[0][u];
}
while (l != v) {
vl.pb(v);
v = par[0][v];
}
ul.pb(l);
ul.insert(ul.end(), rall(vl));
return ul;
}
};
class M {
public:
using S = int;
static constexpr S e = inf;
// requirement : op(l, r) = op(r, l)
static constexpr S op(const S &l, const S &r) {
return min(l, r);
}
};
int main() {
INT(n);
vvp G = weighted_graph<int>(n, n - 1);
LCA<M> lca(G);
int ok = inf, ng = -1;
auto f = [&](int x) -> bool {
int nd = 0;
int u = -1, v = -1, uv = -1;
rep(i, n - 1) for (auto[j, c]: G[i]) {
if (c <= x) continue;
chmax(nd, c - x);
if (u == -1) {
u = i, v = j;
uv = lca.dist(u, v);
continue;
}
int ui = lca.dist(u, i);
int uj = lca.dist(u, j);
int vi = lca.dist(v, i);
int vj = lca.dist(v, j);
if (uv == ui + 1 + vj) continue;
if (uv == uj + 1 + vi) continue;
if (ui == uv + vj + 1) {
v = i;
uv = ui;
continue;
}
if (uj == uv + vi + 1) {
v = j;
uv = uj;
continue;
}
if (vi == uv + uj + 1) {
u = i;
uv = vi;
continue;
}
if (vj == uv + ui + 1) {
u = j;
uv = vj;
continue;
}
return false;
}
if (!nd) return true;
return lca.prod(u, v) >= nd;
};
while (abs(ok - ng) > 1) {
int mid = (ng + ok) / 2;
if (f(mid)) ok = mid;
else ng = mid;
}
fin(ok);
}