#773913 (C++23) No.1976 Cut then Connect

提出ソース

結果

問題	No.1976 Cut then Connect
ユーザー	👑 hitonanode
提出日時	2022-06-26 10:13:49
言語	C++23 (gcc 12.3.0 + boost 1.83.0)
結果	AC
実行時間	61 ms / 2,000 ms
コード長	9,238 bytes
コンパイル時間	2,023 ms
コンパイル使用メモリ	188,048 KB
実行使用メモリ	18,868 KB
最終ジャッジ日時	2024-05-03 12:22:55
合計ジャッジ時間	3,707 ms
ジャッジサーバーID （参考情報）	judge1 / judge5

このコードへのチャレンジ
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テストケース

テストケース表示

入力	結果	実行時間実行使用メモリ
testcase_00	AC	2 ms 6,812 KB
testcase_01	AC	1 ms 6,940 KB
testcase_02	AC	58 ms 18,264 KB
testcase_03	AC	33 ms 11,968 KB
testcase_04	AC	13 ms 6,940 KB
testcase_05	AC	27 ms 10,828 KB
testcase_06	AC	42 ms 15,064 KB
testcase_07	AC	29 ms 11,116 KB
testcase_08	AC	61 ms 18,868 KB
testcase_09	AC	52 ms 16,648 KB
testcase_10	AC	14 ms 7,168 KB
testcase_11	AC	61 ms 18,688 KB
testcase_12	AC	3 ms 6,944 KB
testcase_13	AC	43 ms 15,072 KB
testcase_14	AC	40 ms 14,272 KB
testcase_15	AC	39 ms 13,900 KB
testcase_16	AC	55 ms 17,432 KB
testcase_17	AC	20 ms 8,684 KB
testcase_18	AC	5 ms 6,940 KB
testcase_19	AC	43 ms 14,868 KB
testcase_20	AC	60 ms 18,832 KB
testcase_21	AC	34 ms 12,592 KB
testcase_22	AC	2 ms 6,940 KB
testcase_23	AC	1 ms 6,940 KB
testcase_24	AC	1 ms 6,944 KB
testcase_25	AC	1 ms 6,940 KB
testcase_26	AC	2 ms 6,940 KB
testcase_27	AC	2 ms 6,940 KB
testcase_28	AC	2 ms 6,940 KB
testcase_29	AC	2 ms 6,940 KB
testcase_30	AC	2 ms 6,940 KB
testcase_31	AC	2 ms 6,940 KB
testcase_32	AC	2 ms 6,944 KB

権限があれば一括ダウンロードができます

ソースコード

raw source code

#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 >= 201703L
template <typename... T> istream &operator>>(istream &is, tuple<T...> &tpl) { std::apply([&is](auto &&... args) { ((is >> args), ...);}, tpl); return is; }
template <typename... T> ostream &operator<<(ostream &os, const tuple<T...> &tpl) { os << '('; std::apply([&os](auto &&... args) { ((os << args << ','), ...);}, tpl); return os << ')'; }
#endif
template <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_LOCAL
const 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) 0
#define dbgif(cond, x) 0
#endif

// Rerooting
// Reference:
// - https://atcoder.jp/contests/abc222/editorial/2749
// - https://null-mn.hatenablog.com/entry/2020/04/14/124151
template <class Edge, class St, class Ch, Ch (*merge)(Ch, Ch), Ch (*f)(St, int, Edge),
          St (*g)(Ch, int), Ch (*e)()>
struct rerooting {
    int n_;
    std::vector<int> par, visited;
    std::vector<std::vector<std::pair<int, Edge>>> to;
    std::vector<St> dp_subtree;
    std::vector<St> dp_par;
    std::vector<St> dpall;
    rerooting(const std::vector<std::vector<std::pair<int, Edge>>> &to_)
        : n_(to_.size()), par(n_, -1), visited(n_, 0), to(to_) {
        for (int i = 0; i < n_; ++i) dp_subtree.push_back(g(e(), i));
        dp_par = dpall = dp_subtree;
    }

    void run_connected(int root) {
        if (visited[root]) return;
        visited[root] = 1;
        std::vector<int> visorder{root};

        for (int t = 0; t < int(visorder.size()); ++t) {
            int now = visorder[t];
            for (const auto &edge : to[now]) {
                int nxt = edge.first;
                if (visited[nxt]) continue;
                visorder.push_back(nxt);
                visited[nxt] = 1;
                par[nxt] = now;
            }
        }

        for (int t = int(visorder.size()) - 1; t >= 0; --t) {
            int now = visorder[t];
            Ch ch = e();
            for (const auto &edge : to[now]) {
                int nxt = edge.first;
                if (nxt == par[now]) continue;
                ch = merge(ch, f(dp_subtree[nxt], nxt, edge.second));
            }
            dp_subtree[now] = g(ch, now);
        }

        std::vector<Ch> left;
        for (int now : visorder) {
            int m = int(to[now].size());
            left.assign(m + 1, e());
            for (int j = 0; j < m; j++) {
                int nxt = to[now][j].first;
                const St &st = (nxt == par[now] ? dp_par[now] : dp_subtree[nxt]);
                left[j + 1] = merge(left[j], f(st, nxt, to[now][j].second));
            }
            dpall[now] = g(left.back(), now);

            Ch rprod = e();
            for (int j = m - 1; j >= 0; --j) {
                int nxt = to[now][j].first;
                if (nxt != par[now]) dp_par[nxt] = g(merge(left[j], rprod), now);

                const St &st = (nxt == par[now] ? dp_par[now] : dp_subtree[nxt]);
                rprod = merge(f(st, nxt, to[now][j].second), rprod);
            }
        }
    }

    void run() {
        for (int i = 0; i < n_; ++i) {
            if (!visited[i]) run_connected(i);
        }
    }
};
/* Template:
struct Subtree {};
struct Child {};
struct Edge {};
Child e() { return Child(); }
Child merge(Child x, Child y) { return Child(); }
Child f(Subtree x, int ch_id, Edge edge) { return Child(); }
Subtree g(Child x, int v_id) { return Subtree(); }

vector<vector<pair<int, Edge>>> to;
rerooting<Edge, Subtree, Child, merge, f, g, e> tree(to);
*/

constexpr int INF = 1 << 24;
struct Subtree {
    int diameter;
    int depth;
};
using Child = Subtree;
struct Edge {};
Child e() { return Child{0, -INF}; }
Child merge(Child x, Child y) {
    return Child{max<int>({x.diameter, y.diameter, x.depth + y.depth}), max(x.depth, y.depth)};
}
Child f(Subtree x, int, Edge) {
    ++x.depth;
    chmax(x.diameter, x.depth);
    return x;
}
Subtree g(Child x, int) {
    if (x.depth < 0) return {0, 0};
    return x;
}

int main() {
    int N;
    cin >> N;
    vector<vector<pair<int, Edge>>> to(N);
    REP(e, N - 1) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        to[u].emplace_back(v, Edge{});
        to[v].emplace_back(u, Edge{});
    }
    rerooting<Edge, Subtree, Child, merge, f, g, e> tree(to);
    tree.run_connected(0);
    int ret = N;
    FOR(i, 1, N) {
        chmin(ret, max({
                       tree.dp_subtree[i].diameter,
                       tree.dp_par[i].diameter,
                       1 + (tree.dp_subtree[i].diameter + 1) / 2 + (tree.dp_par[i].diameter + 1) / 2,
                   }));
    }

    cout << ret << endl;
}

yukicoder

結果

テストケース

ソースコード