結果

問題 No.1254 補強への架け橋
ユーザー 👑 emthrmemthrm
提出日時 2021-04-19 04:57:52
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 213 ms / 2,000 ms
コード長 4,594 bytes
コンパイル時間 2,947 ms
コンパイル使用メモリ 235,816 KB
実行使用メモリ 32,872 KB
最終ジャッジ日時 2024-07-04 04:57:41
合計ジャッジ時間 15,876 ms
ジャッジサーバーID
(参考情報)
judge4 / judge5
このコードへのチャレンジ
(要ログイン)

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 2 ms
6,944 KB
testcase_02 AC 2 ms
6,940 KB
testcase_03 AC 2 ms
6,940 KB
testcase_04 AC 2 ms
6,940 KB
testcase_05 AC 1 ms
6,944 KB
testcase_06 AC 2 ms
6,940 KB
testcase_07 AC 2 ms
6,940 KB
testcase_08 AC 2 ms
6,940 KB
testcase_09 AC 2 ms
6,940 KB
testcase_10 AC 2 ms
6,944 KB
testcase_11 AC 2 ms
6,940 KB
testcase_12 AC 2 ms
6,940 KB
testcase_13 AC 2 ms
6,944 KB
testcase_14 AC 2 ms
6,944 KB
testcase_15 AC 1 ms
6,944 KB
testcase_16 AC 2 ms
6,940 KB
testcase_17 AC 2 ms
6,940 KB
testcase_18 AC 1 ms
6,948 KB
testcase_19 AC 2 ms
6,940 KB
testcase_20 AC 2 ms
6,940 KB
testcase_21 AC 2 ms
6,940 KB
testcase_22 AC 2 ms
6,940 KB
testcase_23 AC 2 ms
6,944 KB
testcase_24 AC 2 ms
6,940 KB
testcase_25 AC 2 ms
6,940 KB
testcase_26 AC 2 ms
6,944 KB
testcase_27 AC 2 ms
6,944 KB
testcase_28 AC 2 ms
6,944 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
testcase_33 AC 2 ms
6,944 KB
testcase_34 AC 2 ms
6,940 KB
testcase_35 AC 2 ms
6,940 KB
testcase_36 AC 2 ms
6,940 KB
testcase_37 AC 2 ms
6,940 KB
testcase_38 AC 2 ms
6,944 KB
testcase_39 AC 2 ms
6,944 KB
testcase_40 AC 2 ms
6,940 KB
testcase_41 AC 2 ms
6,940 KB
testcase_42 AC 2 ms
6,940 KB
testcase_43 AC 2 ms
6,944 KB
testcase_44 AC 2 ms
6,944 KB
testcase_45 AC 2 ms
6,940 KB
testcase_46 AC 3 ms
6,944 KB
testcase_47 AC 2 ms
6,940 KB
testcase_48 AC 2 ms
6,940 KB
testcase_49 AC 2 ms
6,944 KB
testcase_50 AC 3 ms
6,940 KB
testcase_51 AC 2 ms
6,940 KB
testcase_52 AC 3 ms
6,944 KB
testcase_53 AC 3 ms
6,944 KB
testcase_54 AC 3 ms
6,940 KB
testcase_55 AC 3 ms
6,940 KB
testcase_56 AC 2 ms
6,944 KB
testcase_57 AC 2 ms
6,944 KB
testcase_58 AC 3 ms
6,944 KB
testcase_59 AC 2 ms
6,944 KB
testcase_60 AC 2 ms
6,944 KB
testcase_61 AC 2 ms
6,944 KB
testcase_62 AC 2 ms
6,940 KB
testcase_63 AC 11 ms
6,940 KB
testcase_64 AC 4 ms
6,940 KB
testcase_65 AC 7 ms
6,940 KB
testcase_66 AC 6 ms
6,944 KB
testcase_67 AC 3 ms
6,940 KB
testcase_68 AC 7 ms
6,944 KB
testcase_69 AC 9 ms
6,940 KB
testcase_70 AC 4 ms
6,940 KB
testcase_71 AC 4 ms
6,940 KB
testcase_72 AC 8 ms
6,944 KB
testcase_73 AC 4 ms
6,940 KB
testcase_74 AC 8 ms
6,940 KB
testcase_75 AC 6 ms
6,944 KB
testcase_76 AC 3 ms
6,940 KB
testcase_77 AC 6 ms
6,940 KB
testcase_78 AC 10 ms
6,944 KB
testcase_79 AC 11 ms
6,944 KB
testcase_80 AC 9 ms
6,944 KB
testcase_81 AC 11 ms
6,944 KB
testcase_82 AC 11 ms
6,940 KB
testcase_83 AC 177 ms
22,368 KB
testcase_84 AC 150 ms
21,940 KB
testcase_85 AC 75 ms
15,032 KB
testcase_86 AC 130 ms
19,480 KB
testcase_87 AC 148 ms
20,812 KB
testcase_88 AC 16 ms
6,940 KB
testcase_89 AC 161 ms
22,364 KB
testcase_90 AC 89 ms
15,664 KB
testcase_91 AC 67 ms
13,080 KB
testcase_92 AC 30 ms
8,524 KB
testcase_93 AC 123 ms
18,636 KB
testcase_94 AC 106 ms
17,080 KB
testcase_95 AC 112 ms
16,956 KB
testcase_96 AC 157 ms
21,476 KB
testcase_97 AC 54 ms
11,644 KB
testcase_98 AC 148 ms
21,644 KB
testcase_99 AC 83 ms
14,444 KB
testcase_100 AC 165 ms
22,832 KB
testcase_101 AC 27 ms
8,016 KB
testcase_102 AC 14 ms
6,944 KB
testcase_103 AC 29 ms
8,320 KB
testcase_104 AC 41 ms
10,296 KB
testcase_105 AC 117 ms
18,704 KB
testcase_106 AC 61 ms
12,816 KB
testcase_107 AC 166 ms
22,268 KB
testcase_108 AC 159 ms
21,944 KB
testcase_109 AC 119 ms
18,420 KB
testcase_110 AC 103 ms
16,932 KB
testcase_111 AC 126 ms
18,044 KB
testcase_112 AC 42 ms
9,984 KB
testcase_113 AC 102 ms
16,620 KB
testcase_114 AC 61 ms
12,084 KB
testcase_115 AC 18 ms
6,944 KB
testcase_116 AC 70 ms
13,504 KB
testcase_117 AC 42 ms
9,984 KB
testcase_118 AC 140 ms
21,236 KB
testcase_119 AC 79 ms
14,324 KB
testcase_120 AC 148 ms
21,528 KB
testcase_121 AC 35 ms
8,960 KB
testcase_122 AC 67 ms
13,340 KB
testcase_123 AC 2 ms
6,940 KB
testcase_124 AC 209 ms
32,616 KB
testcase_125 AC 213 ms
32,872 KB
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ソースコード

diff #

#define _USE_MATH_DEFINES
#include <bits/stdc++.h>
using namespace std;
#define FOR(i,m,n) for(int i=(m);i<(n);++i)
#define REP(i,n) FOR(i,0,n)
#define ALL(v) (v).begin(),(v).end()
using ll = long long;
constexpr int INF = 0x3f3f3f3f;
constexpr long long LINF = 0x3f3f3f3f3f3f3f3fLL;
constexpr double EPS = 1e-8;
constexpr int MOD = 1000000007;
// constexpr int MOD = 998244353;
constexpr int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1};
constexpr int dy8[] = {1, 1, 0, -1, -1, -1, 0, 1}, dx8[] = {0, -1, -1, -1, 0, 1, 1, 1};
template <typename T, typename U> inline bool chmax(T &a, U b) { return a < b ? (a = b, true) : false; }
template <typename T, typename U> inline bool chmin(T &a, U b) { return a > b ? (a = b, true) : false; }
struct IOSetup {
  IOSetup() {
    std::cin.tie(nullptr);
    std::ios_base::sync_with_stdio(false);
    std::cout << fixed << setprecision(20);
  }
} iosetup;

template <typename CostType>
struct Edge {
  int src, dst; CostType cost;
  Edge(int src, int dst, CostType cost = 0) : src(src), dst(dst), cost(cost) {}
  inline bool operator<(const Edge &x) const {
    return cost != x.cost ? cost < x.cost : dst != x.dst ? dst < x.dst : src < x.src;
  }
  inline bool operator<=(const Edge &x) const { return !(x < *this); }
  inline bool operator>(const Edge &x) const { return x < *this; }
  inline bool operator>=(const Edge &x) const { return !(*this < x); }
};

template <typename CostType>
struct UnicyclicGraph {
  std::vector<Edge<CostType>> loop;
  std::vector<bool> is_in_loop;
  std::vector<std::vector<std::vector<Edge<CostType>>>> forest;
  std::vector<int> belong, mp;
  std::vector<std::vector<int>> inv;

  UnicyclicGraph(int n) : n(n), is_in_loop(n, false), belong(n, -1), mp(n, -1), graph(n) {}

  void add_edge(int src_i, int dst_i, CostType cost_i) {
    int id = src.size();
    graph[src_i].emplace_back(id);
    graph[dst_i].emplace_back(id);
    src.emplace_back(src_i);
    dst.emplace_back(dst_i);
    cost.emplace_back(cost_i);
  }

  void build() {
    dfs(-1, 0);
    for (int i = 0; i < n; ++i) {
      if (is_in_loop[i] && graph[i].size() > 2) {
        int idx = forest.size();
        forest.emplace_back(std::vector<std::vector<Edge<CostType>>>(1));
        belong[i] = idx;
        mp[i] = 0;
        inv.emplace_back(std::vector<int>{i});
        std::queue<int> que({i});
        while (!que.empty()) {
          int ver = que.front();
          que.pop();
          for (int id : graph[ver]) {
            int to = destination(id, ver);
            if (belong[to] == -1 && !is_in_loop[to]) {
              int nx = forest[idx].size();
              forest[idx].emplace_back();
              forest[idx][mp[ver]].emplace_back(mp[ver], nx, cost[id]);
              forest[idx][nx].emplace_back(nx, mp[ver], cost[id]);
              belong[to] = idx;
              mp[to] = nx;
              inv[idx].emplace_back(to);
              que.emplace(to);
            }
          }
        }
      }
    }
  }

private:
  int n;
  std::vector<std::vector<int>> graph;
  std::vector<int> src, dst;
  std::vector<CostType> cost;

  int destination(int id, int s) const {
    return src[id] == s ? dst[id] : src[id];
  }

  bool dfs(int prev_id, int ver) {
    is_in_loop[ver] = true;
    for (int id : graph[ver]) {
      if (id != prev_id) {
        int to = destination(id, ver);
        loop.emplace_back(ver, to, cost[id]);
        if (is_in_loop[to]) {
          for (int i = static_cast<int>(loop.size()) - 2; i >= 0; --i) {
            if (loop[i].src == to) {
              for (int j = 0; j < i; ++j) is_in_loop[loop[j].src] = false;
              loop.erase(loop.begin(), loop.begin() + i);
              break;
            }
          }
          return true;
        }
        if (dfs(id, to)) return true;
        loop.pop_back();
      }
    }
    is_in_loop[ver] = false;
    return false;
  }
};

int main() {
  int n;
  std::cin >> n;
  std::map<std::pair<int, int>, int> edge;
  UnicyclicGraph<bool> namori(n);
  for (int i = 0; i < n; ++i) {
    int a, b;
    std::cin >> a >> b;
    --a; --b;
    if (a > b) std::swap(a, b);
    edge[{a, b}] = i;
    namori.add_edge(a, b, false);
  }
  namori.build();
  std::vector<bool> bridge(n, false);
  for (const Edge<bool> &e : namori.loop) {
    int a = e.src, b = e.dst;
    if (a > b) std::swap(a, b);
    bridge[edge[{a, b}]] = true;
  }
  std::vector<int> p;
  for (int i = 0; i < n; ++i) {
    if (bridge[i]) p.emplace_back(i);
  }
  int k = p.size();
  std::cout << k << '\n';
  for (int i = 0; i < k; ++i) std::cout << p[i] + 1 << " \n"[i + 1 == k];
  return 0;
}
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