結果
| 問題 | No.1833 Subway Planning |
| ユーザー |
 hitonanode
|
| 提出日時 | 2022-02-04 22:45:12 |
| 言語 | C++23 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 1,300 ms / 4,000 ms |
| コード長 | 10,460 bytes |
| コンパイル時間 | 2,929 ms |
| コンパイル使用メモリ | 204,684 KB |
| 実行使用メモリ | 122,116 KB |
| 最終ジャッジ日時 | 2024-06-11 12:13:53 |
| 合計ジャッジ時間 | 13,705 ms |
|
ジャッジサーバーID （参考情報） |
judge4 / judge3 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 23 |
ソースコード
#include <algorithm>#include <array>#include <bitset>#include <cassert>#include <chrono>#include <cmath>#include <complex>#include <deque>#include <forward_list>#include <fstream>#include <functional>#include <iomanip>#include <ios>#include <iostream>#include <limits>#include <list>#include <map>#include <numeric>#include <queue>#include <random>#include <set>#include <sstream>#include <stack>#include <string>#include <tuple>#include <type_traits>#include <unordered_map>#include <unordered_set>#include <utility>#include <vector>using namespace std;using lint = long long;using pint = pair<int, int>;using plint = pair<lint, lint>;struct fast_ios { fast_ios(){ cin.tie(nullptr), ios::sync_with_stdio(false), cout << fixed << setprecision(20); }; } fast_ios_;#define ALL(x) (x).begin(), (x).end()#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)#define REP(i, n) FOR(i,0,n)#define IREP(i, n) IFOR(i,0,n)template <typename T, typename V>void ndarray(vector<T>& vec, const V& val, int len) { vec.assign(len, val); }template <typename T, typename V, typename... Args> void ndarray(vector<T>& vec, const V& val, int len, Args... args) { vec.resize(len), for_each(begin(vec), end(vec), [&](T& v) { ndarray(v, val, args...); }); }template <typename T> bool chmax(T &m, const T q) { return m < q ? (m = q, true) : false; }template <typename T> bool chmin(T &m, const T q) { return m > q ? (m = q, true) : false; }int floor_lg(long long x) { return x <= 0 ? -1 : 63 - __builtin_clzll(x); }template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }template <typename T> vector<T> sort_unique(vector<T> vec) { sort(vec.begin(), vec.end()), vec.erase(unique(vec.begin(), vec.end()), vec.end());return vec; }template <typename T> int arglb(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::lower_bound(v.begin(), v.end(), x)); }template <typename T> int argub(const std::vector<T> &v, const T &x) { return std::distance(v.begin(), std::upper_bound(v.begin(), v.end(), x)); }template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << '['; for (auto v : vec) os << v << ','; os << ']'; return os; }template <typename T, size_t sz> ostream &operator<<(ostream &os, const array<T, sz> &arr) { os << '['; for (auto v : arr) os << v << ','; os << ']';return os; }#if __cplusplus >= 201703Ltemplate <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); returnis; }template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }#endiftemplate <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ','; os << ']'; return os;}template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os; }template <typename T, typename TH> ostream &operator<<(ostream &os, const unordered_set<T, TH> &vec) { os << '{'; for (auto v : vec) os << v << ',';os << '}'; return os; }template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}'; return os;}template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << '{'; for (auto v : vec) os << v << ','; os << '}';return os; }template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << '(' << pa.first << ',' << pa.second << ')';return os; }template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << '{'; for (auto v : mp) os << v.first << "=>" << v.second << ','; os << '}'; return os; }template <typename TK, typename TV, typename TH> ostream &operator<<(ostream &os, const unordered_map<TK, TV, TH> &mp) { os << '{'; for (auto v : mp)os << v.first << "=>" << v.second << ','; os << '}'; return os; }#ifdef HITONANODE_LOCALconst string COLOR_RESET = "\033[0m", BRIGHT_GREEN = "\033[1;32m", BRIGHT_RED = "\033[1;31m", BRIGHT_CYAN = "\033[1;36m", NORMAL_CROSSED = "\033[0;9;37m", RED_BACKGROUND = "\033[1;41m", NORMAL_FAINT = "\033[0;2m";#define dbg(x) cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ << COLOR_RESET <<endl#define dbgif(cond, x) ((cond) ? cerr << BRIGHT_CYAN << #x << COLOR_RESET << " = " << (x) << NORMAL_FAINT << " (L" << __LINE__ << ") " << __FILE__ <<COLOR_RESET << endl : cerr)#else#define dbg(x) (x)#define dbgif(cond, x) 0#endif// Range Minimum Query for static sequence by sparse table// Complexity: (N \log N)$ for precalculation, (1)$ per querytemplate <typename T> struct StaticRMQ {inline T func(const T &l, const T &r) const noexcept { return std::min<T>(l, r); }int N, lgN;T defaultT;std::vector<std::vector<T>> data;std::vector<int> lgx_table;StaticRMQ() = default;StaticRMQ(const std::vector<T> &sequence, T defaultT): N(sequence.size()), defaultT(defaultT) {lgx_table.resize(N + 1);for (int i = 2; i < N + 1; i++) lgx_table[i] = lgx_table[i >> 1] + 1;lgN = lgx_table[N] + 1;data.assign(lgN, std::vector<T>(N, defaultT));data[0] = sequence;for (int d = 1; d < lgN; d++) {for (int i = 0; i + (1 << d) <= N; i++) {data[d][i] = func(data[d - 1][i], data[d - 1][i + (1 << (d - 1))]);}}}T get(int l, int r) const { // [l, r), 0-indexedassert(l >= 0 and r <= N);if (l >= r) return defaultT;int d = lgx_table[r - l];return func(data[d][l], data[d][r - (1 << d)]);}};struct TreeLCA {const int N;std::vector<std::vector<int>> to;bool built;TreeLCA(int V = 0) : N(V), to(V), built(false) {}void add_edge(int u, int v) {assert(0 <= u and u < N);assert(0 <= v and v < N);assert(u != v);to[u].push_back(v);to[v].push_back(u);}using P = std::pair<int, int>;std::vector<int> subtree_begin;std::vector<P> vis_order;std::vector<int> depth;void _build_dfs(int now, int prv, int dnow) {subtree_begin[now] = vis_order.size();vis_order.emplace_back(dnow, now);depth[now] = dnow;for (auto &&nxt : to[now]) {if (nxt != prv) {_build_dfs(nxt, now, dnow + 1);vis_order.emplace_back(dnow, now);}}}StaticRMQ<P> rmq;void build(int root = 0) {assert(root >= 0 and root < N);built = true;subtree_begin.resize(N);vis_order.reserve(N * 2);depth.resize(N);_build_dfs(root, -1, 0);rmq = {vis_order, P{N, -1}};}int lca(int u, int v) {assert(0 <= u and u < N);assert(0 <= v and v < N);if (!built) build();auto a = subtree_begin[u], b = subtree_begin[v];if (a > b) std::swap(a, b);return rmq.get(a, b + 1).second;};int path_length(int u, int v) { return depth[u] + depth[v] - depth[lca(u, v)] * 2; }};// UnionFind Tree (0-indexed), based on size of each disjoint setstruct UnionFind {std::vector<int> par, cou;UnionFind(int N = 0) : par(N), cou(N, 1) { iota(par.begin(), par.end(), 0); }int find(int x) { return (par[x] == x) ? x : (par[x] = find(par[x])); }bool unite(int x, int y) {x = find(x), y = find(y);if (x == y) return false;if (cou[x] < cou[y]) std::swap(x, y);par[y] = x, cou[x] += cou[y];return true;}int count(int x) { return cou[find(x)]; }bool same(int x, int y) { return find(x) == find(y); }};int main() {int N;cin >> N;vector<tuple<int, int, int>> edges;TreeLCA graph(N);int ng = -1, ok = 0;vector<vector<pint>> to(N);REP(i, N - 1) {int a, b, c;cin >> a >> b >> c;--a, --b;edges.emplace_back(a, b, c);chmax(ok, c);graph.add_edge(a, b);to[a].emplace_back(b, c);to[b].emplace_back(a, c);}const int maxi = ok;const int root = 0;graph.build(root);vector<pint> par(N, pint(-1, -1));auto rec = [&](auto &&self, int now, int prv) -> void {for (auto [nxt, w] : to[now]) {if (nxt == prv) continue;par[nxt] = pint(now, w);self(self, nxt, now);}};rec(rec, root, -1);dbg(par);while (ok > ng + 1) {const int m = (ok + ng) / 2;UnionFind uf(N);vector<pint> dvs;int lca = -1;for (auto [a, b, w] : edges) {if (w > m) {if (lca < 0) lca = a;lca = graph.lca(lca, a);lca = graph.lca(lca, b);uf.unite(a, b);dvs.emplace_back(graph.depth[a], a);dvs.emplace_back(graph.depth[b], b);}}dvs = sort_unique(dvs);reverse(ALL(dvs));vector<int> vis(N);vector<int> deg(N);if (lca >= 0) deg[lca] -= 1;bool failed = false;for (auto [d, v] : dvs) {if (vis[v]) continue;vis[v] = 1;while (v != lca) {if (par[v].second < maxi - m) {failed = true;break;}v = par[v].first;deg[v]++;vis[v] = 1;}}dbgif(m == 8, vis);dbgif(m == 8, deg);dbgif(m == 8, failed);dbgif(m == 8, dvs);if (*max_element(ALL(deg)) > 1) failed = true;(failed ? ng : ok) = m;}cout << ok << '\n';}