結果

問題 No.1254 補強への架け橋
ユーザー iiljjiiljj
提出日時 2020-10-09 22:49:51
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 256 ms / 2,000 ms
コード長 8,900 bytes
コンパイル時間 2,963 ms
コンパイル使用メモリ 234,764 KB
実行使用メモリ 40,660 KB
最終ジャッジ日時 2024-07-20 13:17:45
合計ジャッジ時間 16,073 ms
ジャッジサーバーID
（参考情報） 		judge4 / judge3
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 1 ms
5,248 KB
testcase_01 AC 1 ms
5,376 KB
testcase_02 AC 2 ms
5,376 KB
testcase_03 AC 2 ms
5,376 KB
testcase_04 AC 2 ms
5,376 KB
testcase_05 AC 1 ms
5,376 KB
testcase_06 AC 1 ms
5,376 KB
testcase_07 AC 2 ms
5,376 KB
testcase_08 AC 1 ms
5,376 KB
testcase_09 AC 2 ms
5,376 KB
testcase_10 AC 1 ms
5,376 KB
testcase_11 AC 2 ms
5,376 KB
testcase_12 AC 2 ms
5,376 KB
testcase_13 AC 1 ms
5,376 KB
testcase_14 AC 2 ms
5,376 KB
testcase_15 AC 2 ms
5,376 KB
testcase_16 AC 1 ms
5,376 KB
testcase_17 AC 2 ms
5,376 KB
testcase_18 AC 2 ms
5,376 KB
testcase_19 AC 2 ms
5,376 KB
testcase_20 AC 1 ms
5,376 KB
testcase_21 AC 2 ms
5,376 KB
testcase_22 AC 2 ms
5,376 KB
testcase_23 AC 2 ms
5,376 KB
testcase_24 AC 2 ms
5,376 KB
testcase_25 AC 2 ms
5,376 KB
testcase_26 AC 2 ms
5,376 KB
testcase_27 AC 1 ms
5,376 KB
testcase_28 AC 1 ms
5,376 KB
testcase_29 AC 2 ms
5,376 KB
testcase_30 AC 2 ms
5,376 KB
testcase_31 AC 2 ms
5,376 KB
testcase_32 AC 2 ms
5,376 KB
testcase_33 AC 1 ms
5,376 KB
testcase_34 AC 2 ms
5,376 KB
testcase_35 AC 2 ms
5,376 KB
testcase_36 AC 2 ms
5,376 KB
testcase_37 AC 1 ms
5,376 KB
testcase_38 AC 2 ms
5,376 KB
testcase_39 AC 2 ms
5,376 KB
testcase_40 AC 1 ms
5,376 KB
testcase_41 AC 2 ms
5,376 KB
testcase_42 AC 2 ms
5,376 KB
testcase_43 AC 2 ms
5,376 KB
testcase_44 AC 2 ms
5,376 KB
testcase_45 AC 2 ms
5,376 KB
testcase_46 AC 2 ms
5,376 KB
testcase_47 AC 2 ms
5,376 KB
testcase_48 AC 3 ms
5,376 KB
testcase_49 AC 2 ms
5,376 KB
testcase_50 AC 3 ms
5,376 KB
testcase_51 AC 3 ms
5,376 KB
testcase_52 AC 2 ms
5,376 KB
testcase_53 AC 2 ms
5,376 KB
testcase_54 AC 3 ms
5,376 KB
testcase_55 AC 2 ms
5,376 KB
testcase_56 AC 2 ms
5,376 KB
testcase_57 AC 2 ms
5,376 KB
testcase_58 AC 2 ms
5,376 KB
testcase_59 AC 2 ms
5,376 KB
testcase_60 AC 2 ms
5,376 KB
testcase_61 AC 2 ms
5,376 KB
testcase_62 AC 2 ms
5,376 KB
testcase_63 AC 16 ms
6,016 KB
testcase_64 AC 5 ms
5,376 KB
testcase_65 AC 11 ms
5,376 KB
testcase_66 AC 8 ms
5,376 KB
testcase_67 AC 4 ms
5,376 KB
testcase_68 AC 9 ms
5,376 KB
testcase_69 AC 13 ms
5,376 KB
testcase_70 AC 6 ms
5,376 KB
testcase_71 AC 5 ms
5,376 KB
testcase_72 AC 12 ms
5,376 KB
testcase_73 AC 5 ms
5,376 KB
testcase_74 AC 12 ms
5,376 KB
testcase_75 AC 9 ms
5,376 KB
testcase_76 AC 3 ms
5,376 KB
testcase_77 AC 8 ms
5,376 KB
testcase_78 AC 15 ms
5,760 KB
testcase_79 AC 15 ms
5,760 KB
testcase_80 AC 13 ms
5,392 KB
testcase_81 AC 16 ms
5,632 KB
testcase_82 AC 14 ms
5,632 KB
testcase_83 AC 235 ms
28,112 KB
testcase_84 AC 256 ms
27,336 KB
testcase_85 AC 123 ms
18,012 KB
testcase_86 AC 192 ms
24,444 KB
testcase_87 AC 231 ms
26,264 KB
testcase_88 AC 24 ms
7,168 KB
testcase_89 AC 239 ms
27,932 KB
testcase_90 AC 144 ms
18,936 KB
testcase_91 AC 97 ms
15,948 KB
testcase_92 AC 48 ms
9,984 KB
testcase_93 AC 178 ms
23,484 KB
testcase_94 AC 165 ms
21,912 KB
testcase_95 AC 156 ms
21,612 KB
testcase_96 AC 220 ms
26,680 KB
testcase_97 AC 84 ms
14,284 KB
testcase_98 AC 239 ms
27,048 KB
testcase_99 AC 120 ms
17,512 KB
testcase_100 AC 244 ms
28,540 KB
testcase_101 AC 42 ms
9,216 KB
testcase_102 AC 22 ms
6,528 KB
testcase_103 AC 45 ms
9,856 KB
testcase_104 AC 65 ms
12,720 KB
testcase_105 AC 177 ms
23,632 KB
testcase_106 AC 90 ms
15,168 KB
testcase_107 AC 250 ms
27,956 KB
testcase_108 AC 230 ms
27,384 KB
testcase_109 AC 176 ms
23,412 KB
testcase_110 AC 158 ms
21,708 KB
testcase_111 AC 171 ms
22,872 KB
testcase_112 AC 62 ms
11,776 KB
testcase_113 AC 142 ms
20,140 KB
testcase_114 AC 86 ms
14,744 KB
testcase_115 AC 26 ms
7,424 KB
testcase_116 AC 109 ms
16,340 KB
testcase_117 AC 62 ms
12,360 KB
testcase_118 AC 225 ms
26,676 KB
testcase_119 AC 116 ms
17,412 KB
testcase_120 AC 214 ms
25,748 KB
testcase_121 AC 52 ms
10,536 KB
testcase_122 AC 102 ms
16,168 KB
testcase_123 AC 2 ms
5,376 KB
testcase_124 AC 211 ms
40,656 KB
testcase_125 AC 224 ms
40,660 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

diff # 

/* #region Head */

// #define _GLIBCXX_DEBUG
#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pll = pair<ll, ll>;
template <class T> using vc = vector<T>;
template <class T> using vvc = vc<vc<T>>;
using vll = vc<ll>;
using vvll = vvc<ll>;
using vld = vc<ld>;
using vvld = vvc<ld>;
using vs = vc<string>;
using vvs = vvc<string>;
template <class T, class U> using um = unordered_map<T, U>;
template <class T> using pq = priority_queue<T>;
template <class T> using pqa = priority_queue<T, vc<T>, greater<T>>;
template <class T> using us = unordered_set<T>;

#define REP(i, m, n) for (ll i = (m), i##_len = (ll)(n); i < i##_len; ++(i))
#define REPM(i, m, n) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; ++(i))
#define REPR(i, m, n) for (ll i = (m), i##_min = (ll)(n); i >= i##_min; --(i))
#define REPD(i, m, n, d) for (ll i = (m), i##_len = (ll)(n); i < i##_len; i += (d))
#define REPMD(i, m, n, d) for (ll i = (m), i##_max = (ll)(n); i <= i##_max; i += (d))
#define REPI(itr, ds) for (auto itr = ds.begin(); itr != ds.end(); itr++)
#define ALL(x) begin(x), end(x)
#define SIZE(x) ((ll)(x).size())
#define PERM(c)                                                                                                        \
    sort(ALL(c));                                                                                                      \
    for (bool c##p = 1; c##p; c##p = next_permutation(ALL(c)))
#define UNIQ(v) v.erase(unique(ALL(v)), v.end());

#define endl '\n'
#define sqrt sqrtl
#define floor floorl
#define log2 log2l

constexpr ll INF = 1'010'000'000'000'000'017LL;
constexpr int IINF = 1'000'000'007LL;
constexpr ll MOD = 1'000'000'007LL; // 1e9 + 7
// constexpr ll MOD = 998244353;
constexpr ld EPS = 1e-12;
constexpr ld PI = 3.14159265358979323846;

template <typename T> istream &operator>>(istream &is, vc<T> &vec) { // vector 入力
    for (T &x : vec) is >> x;
    return is;
}
template <typename T> ostream &operator<<(ostream &os, vc<T> &vec) { // vector 出力 (for dump)
    os << "{";
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "" : ", ");
    os << "}";
    return os;
}
template <typename T> ostream &operator>>(ostream &os, vc<T> &vec) { // vector 出力 (inline)
    REP(i, 0, SIZE(vec)) os << vec[i] << (i == i_len - 1 ? "\n" : " ");
    return os;
}

template <typename T, typename U> istream &operator>>(istream &is, pair<T, U> &pair_var) { // pair 入力
    is >> pair_var.first >> pair_var.second;
    return is;
}
template <typename T, typename U> ostream &operator<<(ostream &os, pair<T, U> &pair_var) { // pair 出力
    os << "(" << pair_var.first << ", " << pair_var.second << ")";
    return os;
}

// map, um, set, us 出力
template <class T> ostream &out_iter(ostream &os, T &map_var) {
    os << "{";
    REPI(itr, map_var) {
        os << *itr;
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    return os << "}";
}
template <typename T, typename U> ostream &operator<<(ostream &os, map<T, U> &map_var) { return out_iter(os, map_var); }
template <typename T, typename U> ostream &operator<<(ostream &os, um<T, U> &map_var) {
    os << "{";
    REPI(itr, map_var) {
        auto [key, value] = *itr;
        os << "(" << key << ", " << value << ")";
        auto itrcp = itr;
        if (++itrcp != map_var.end()) os << ", ";
    }
    os << "}";
    return os;
}
template <typename T> ostream &operator<<(ostream &os, set<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, us<T> &set_var) { return out_iter(os, set_var); }
template <typename T> ostream &operator<<(ostream &os, pq<T> &pq_var) {
    pq<T> pq_cp(pq_var);
    os << "{";
    if (!pq_cp.empty()) {
        os << pq_cp.top(), pq_cp.pop();
        while (!pq_cp.empty()) os << ", " << pq_cp.top(), pq_cp.pop();
    }
    return os << "}";
}

// dump
#define DUMPOUT cerr
void dump_func() { DUMPOUT << endl; }
template <class Head, class... Tail> void dump_func(Head &&head, Tail &&... tail) {
    DUMPOUT << head;
    if (sizeof...(Tail) > 0) DUMPOUT << ", ";
    dump_func(move(tail)...);
}

// chmax (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmax(T &xmax, const U &x, Comp comp = {}) {
    if (comp(xmax, x)) {
        xmax = x;
        return true;
    }
    return false;
}

// chmin (更新「される」かもしれない値が前)
template <typename T, typename U, typename Comp = less<>> bool chmin(T &xmin, const U &x, Comp comp = {}) {
    if (comp(x, xmin)) {
        xmin = x;
        return true;
    }
    return false;
}

// ローカル用
#define DEBUG_

#ifdef DEBUG_
#define DEB
#define dump(...)                                                                                                      \
    DUMPOUT << "  " << string(#__VA_ARGS__) << ": "                                                                    \
            << "[" << to_string(__LINE__) << ":" << __FUNCTION__ << "]" << endl                                        \
            << "    ",                                                                                                 \
        dump_func(__VA_ARGS__)
#else
#define DEB if (false)
#define dump(...)
#endif

#define VAR(type, ...)                                                                                                 \
    type __VA_ARGS__;                                                                                                  \
    cin >> __VA_ARGS__;

template <typename T> istream &operator,(istream &is, T &rhs) { return is >> rhs; }
template <typename T> ostream &operator,(ostream &os, const T &rhs) { return os << ' ' << rhs; }

struct AtCoderInitialize {
    static constexpr int IOS_PREC = 15;
    static constexpr bool AUTOFLUSH = false;
    AtCoderInitialize() {
        ios_base::sync_with_stdio(false), cin.tie(nullptr), cout.tie(nullptr);
        cout << fixed << setprecision(IOS_PREC);
        if (AUTOFLUSH) cout << unitbuf;
    }
} ATCODER_INITIALIZE;

void Yn(bool p) { cout << (p ? "Yes" : "No") << endl; }
void YN(bool p) { cout << (p ? "YES" : "NO") << endl; }

/* #endregion */

// #include <atcoder/all>
// using namespace atcoder;

struct Edge {
    int to;
};
using Graph = vector<vector<Edge>>;
using P = pair<long, long>;
/* Lowlink: グラフの関節点・橋を列挙する構造体
    作成: O(E+V)
    関節点の集合: vector<int> aps
    橋の集合: vector<P> bridges
*/
struct LowLink {
    const Graph &G;
    vector<int> used, ord, low;
    vector<int> aps; // articulation points
    vector<P> bridges;
    LowLink(const Graph &G_) : G(G_) {
        used.assign(G.size(), 0);
        ord.assign(G.size(), 0);
        low.assign(G.size(), 0);
        int k = 0;
        for (int i = 0; i < (int)G.size(); i++) {
            if (!used[i]) k = dfs(i, k, -1);
        }
        sort(aps.begin(), aps.end());         // 必要ならソートする
        sort(bridges.begin(), bridges.end()); // 必要ならソートする
    }
    int dfs(int id, int k, int par) { // id:探索中の頂点, k:dfsで何番目に探索するか, par:idの親
        used[id] = true;
        ord[id] = k++;
        low[id] = ord[id];
        bool is_aps = false;
        int count = 0; // 子の数
        for (auto &e : G[id]) {
            if (!used[e.to]) {
                count++;
                k = dfs(e.to, k, id);
                low[id] = min(low[id], low[e.to]);
                if (par != -1 && ord[id] <= low[e.to]) is_aps = true;
                if (ord[id] < low[e.to]) bridges.emplace_back(min(id, e.to), max(id, e.to)); // 条件を満たすので橋
            } else if (e.to != par) {                                                        // eが後退辺の時
                low[id] = min(low[id], ord[e.to]);
            }
        }
        if (par == -1 && count >= 2) is_aps = true;
        if (is_aps) aps.push_back(id);
        return k;
    }
};

// Problem
void solve() {
    // 取り去っても木が維持されるような辺を除去したい，そのような辺を探す
    // -> ループからは1個とっても大丈夫

    VAR(ll, n);
    map<P, ll> edgenum;
    set<ll> edgenumset;
    Graph g(n);
    REP(i, 0, n) {
        VAR(int, a, b);
        --a, --b;
        P key0 = {a, b};
        P key1 = {b, a};
        edgenum[key0] = i + 1;
        edgenum[key1] = i + 1;
        g[a].push_back({b});
        g[b].push_back({a});
        edgenumset.insert(i + 1);
    }

    LowLink lnk(g);
    for (auto &bridge : lnk.bridges) {
        ll num = edgenum[bridge];
        edgenumset.erase(num);
    }

    vll out;
    for (ll num : edgenumset) out.push_back(num);
    cout << SIZE(out) << endl;
    cout >> out;
}

// entry point
int main() {
    solve();
    return 0;
}
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