結果

問題 No.1553 Lovely City
ユーザー optopt
提出日時 2021-06-18 23:16:50
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
WA  
実行時間 -
コード長 5,134 bytes
コンパイル時間 4,582 ms
コンパイル使用メモリ 270,568 KB
実行使用メモリ 20,964 KB
最終ジャッジ日時 2024-06-22 21:25:39
合計ジャッジ時間 10,408 ms
ジャッジサーバーID
（参考情報） 		judge2 / judge4
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
5,248 KB
testcase_01 AC 1 ms
5,376 KB
testcase_02 WA -
testcase_03 WA -
testcase_04 WA -
testcase_05 WA -
testcase_06 AC 2 ms
5,376 KB
testcase_07 WA -
testcase_08 WA -
testcase_09 WA -
testcase_10 WA -
testcase_11 WA -
testcase_12 WA -
testcase_13 WA -
testcase_14 WA -
testcase_15 WA -
testcase_16 WA -
testcase_17 WA -
testcase_18 WA -
testcase_19 WA -
testcase_20 WA -
testcase_21 WA -
testcase_22 WA -
testcase_23 WA -
testcase_24 WA -
testcase_25 WA -
testcase_26 WA -
testcase_27 WA -
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 # 

#include<bits/stdc++.h>
using namespace std;
#include<atcoder/all>
using namespace atcoder;
// input and output of modint
istream &operator>>(istream &is, modint998244353 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint998244353 &a) { return os << a.val(); }
istream &operator>>(istream &is, modint1000000007 &a) { long long v; is >> v; a = v; return is; }
ostream &operator<<(ostream &os, const modint1000000007 &a) { return os << a.val(); }
template<int m> istream &operator>>(istream &is, static_modint<m> &a) { long long v; is >> v; a = v; return is; }
template<int m> ostream &operator<<(ostream &os, const static_modint<m> &a) { return os << a.val(); }
template<int m> istream &operator>>(istream &is, dynamic_modint<m> &a) { long long v; is >> v; a = v; return is; }
template<int m> ostream &operator<<(ostream &os, const dynamic_modint<m> &a) { return os << a.val(); }
#define rep_(i, a_, b_, a, b, ...) for (int i = (a), lim##i = (b); i < lim##i; ++i)
#define rep(i, ...) rep_(i, __VA_ARGS__, __VA_ARGS__, 0, __VA_ARGS__)
#define drep_(i, a_, b_, a, b, ...) for (int i = (a)-1, lim##i = (b); i >= lim##i; --i)
#define drep(i, ...) drep_(i, __VA_ARGS__, __VA_ARGS__, __VA_ARGS__, 0)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#ifdef LOCAL
void debug_out() { cerr << endl; }
template <class Head, class... Tail> void debug_out(Head H, Tail... T) { cerr << ' ' << H; debug_out(T...); }
#define debug(...) cerr << 'L' << __LINE__ << " [" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define dump(x) cerr << 'L' << __LINE__ << " " << #x << " = " << (x) << endl
#else
#define debug(...) (void(0))
#define dump(x) (void(0))
#endif
template<class T> using V = vector<T>;
template<class T> using VV = V<V<T>>;
using ll = long long;
using ld = long double;
using Vi = V<int>;  using VVi = VV<int>;
using Vl = V<ll>;   using VVl = VV<ll>;
using Vd = V<ld>;   using VVd = VV<ld>;
using Vb = V<bool>; using VVb = VV<bool>;
template<class T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
template<class T> vector<T> make_vec(size_t n, T a) { return vector<T>(n, a); }
template<class... Ts> auto make_vec(size_t n, Ts... ts) { return vector<decltype(make_vec(ts...))>(n, make_vec(ts...)); }
template<class T> inline int sz(const T &x) { return x.size(); }
template<class T> inline bool chmin(T &a, const T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T &a, const T b) { if (a < b) { a = b; return true; } return false; }
template<class T1, class T2> istream &operator>>(istream &is, pair<T1, T2> &p) { is >> p.first >> p.second; return is; }
template<class T1, class T2> ostream &operator<<(ostream &os, const pair<T1, T2> &p) { os << '(' << p.first << ", " << p.second << ')'; return os; }
template<class T, size_t n> istream &operator>>(istream &is, array<T, n> &v) { for (auto &e : v) is >> e; return is; }
template<class T, size_t n> ostream &operator<<(ostream &os, const  array<T, n> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> istream &operator>>(istream &is, vector<T> &v) { for (auto &e : v) is >> e; return is; }
template<class T> ostream &operator<<(ostream &os, const vector<T> &v) { for (auto &e : v) os << e << '\n'; return os; }
template<class T> istream &operator>>(istream &is, deque<T> &v) { for (auto &e : v) is >> e; return is; }
template<class T> ostream &operator<<(ostream &os, const deque<T> &v) { for (auto &e : v) os << e << ' '; return os; }
template<class T> inline void deduplicate(vector<T> &a) { sort(all(a)); a.erase(unique(all(a)), a.end()); }
template<class T> inline int count_between(const vector<T> &a, T l, T r) { return lower_bound(all(a), r) - lower_bound(all(a), l); } // [l, r)
inline ll ceil_div(const ll x, const ll y) { return (x+y-1) / y; } // ceil(x/y)
inline int floor_log2(const ll x) { assert(x > 0); return 63 - __builtin_clzll(x); } // floor(log2(x))
inline int ceil_log2(const ll x) { assert(x > 0); return (x == 1) ? 0 : 64 - __builtin_clzll(x-1); } // ceil(log2(x))
inline int popcount(const ll x) { return __builtin_popcountll(x); }
inline void fail() { cout << -1 << '\n'; exit(0); }
struct fast_ios { fast_ios(){ cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
// constexpr int INF = numeric_limits<int>::max() >> 1;
// constexpr ll INFll = numeric_limits<ll>::max() >> 1;
// constexpr ld EPS = 1e-10;
// const ld PI = acos(-1.0);
// using mint = modint998244353;
// using mint = modint1000000007;
// using mint = modint;
// using Vm = V<mint>; using VVm = V<Vm>;


void solve() {
  int n, m; cin >> n >> m;
  scc_graph g(n);
  rep(i, m) {
    int u, v; cin >> u >> v;
    --u, --v;
    g.add_edge(u, v);
  }
  auto res = g.scc();

  bool two = false;
  Vi vs;
  for (auto &v : res) {
    two |= (sz(v) > 1);
    vs.insert(vs.end(), all(v));
  }

  V<array<int, 2>> ans;
  rep(i, n-1) ans.push_back({vs[i] + 1, vs[i+1] + 1});
  if (two) ans.push_back({vs[n-1] + 1, vs[0] + 1});

  cout << sz(ans) << '\n';
  cout << ans;
}


int main() {
  solve();
}
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