結果
| 問題 | No.1553 Lovely City |
| ユーザー |
 jell
|
| 提出日時 | 2021-06-19 00:05:55 |
| 言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
| 結果 |
AC
|
| 実行時間 | 284 ms / 2,000 ms |
| コード長 | 44,354 bytes |
| コンパイル時間 | 4,937 ms |
| コンパイル使用メモリ | 297,212 KB |
| 実行使用メモリ | 41,124 KB |
| 最終ジャッジ日時 | 2024-06-22 21:41:57 |
| 合計ジャッジ時間 | 13,669 ms |
|
ジャッジサーバーID （参考情報） |
judge3 / judge4 |
（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
6,816 KB |
| testcase_01 | AC | 1 ms
6,816 KB |
| testcase_02 | AC | 56 ms
20,912 KB |
| testcase_03 | AC | 2 ms
6,940 KB |
| testcase_04 | AC | 2 ms
6,940 KB |
| testcase_05 | AC | 3 ms
6,948 KB |
| testcase_06 | AC | 2 ms
6,940 KB |
| testcase_07 | AC | 2 ms
6,940 KB |
| testcase_08 | AC | 160 ms
25,532 KB |
| testcase_09 | AC | 156 ms
26,684 KB |
| testcase_10 | AC | 183 ms
35,376 KB |
| testcase_11 | AC | 128 ms
23,688 KB |
| testcase_12 | AC | 181 ms
34,664 KB |
| testcase_13 | AC | 133 ms
22,260 KB |
| testcase_14 | AC | 161 ms
26,148 KB |
| testcase_15 | AC | 146 ms
28,116 KB |
| testcase_16 | AC | 182 ms
27,152 KB |
| testcase_17 | AC | 148 ms
27,836 KB |
| testcase_18 | AC | 260 ms
41,024 KB |
| testcase_19 | AC | 284 ms
40,460 KB |
| testcase_20 | AC | 239 ms
38,804 KB |
| testcase_21 | AC | 251 ms
39,252 KB |
| testcase_22 | AC | 259 ms
39,012 KB |
| testcase_23 | AC | 273 ms
40,616 KB |
| testcase_24 | AC | 245 ms
40,588 KB |
| testcase_25 | AC | 242 ms
40,472 KB |
| testcase_26 | AC | 273 ms
41,124 KB |
| testcase_27 | AC | 245 ms
39,248 KB |
ソースコード
#line 1 "other-workspace\\y.cc"
// #undef _GLIBCXX_DEBUG
// #define NDEBUG
#include <bits/extc++.h>
#line 2 "Library\\lib\\alias"
/**
* @file alias
* @brief Alias
*/
#line 10 "Library\\lib\\alias"
#line 2 "Library\\lib\\bit"
#if __cplusplus > 201703L
#include <bit>
#elif __cplusplus > 201402L
#ifndef _GLIBCXX_BIT
#define _GLIBCXX_BIT 1
#include <limits>
#include <type_traits>
namespace std {
template <typename _Tp> constexpr int __countl_zero(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
if (__x == 0) return _Nd;
constexpr auto _Nd_ull = numeric_limits<unsigned long long>::digits;
constexpr auto _Nd_ul = numeric_limits<unsigned long>::digits;
constexpr auto _Nd_u = numeric_limits<unsigned>::digits;
if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u) {
constexpr int __diff = _Nd_u - _Nd;
return __builtin_clz(__x) - __diff;
} else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul) {
constexpr int __diff = _Nd_ul - _Nd;
return __builtin_clzl(__x) - __diff;
} else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull) {
constexpr int __diff = _Nd_ull - _Nd;
return __builtin_clzll(__x) - __diff;
} else // (_Nd > _Nd_ull)
{
static_assert(_Nd <= (2 * _Nd_ull),
"Maximum supported integer size is 128-bit");
unsigned long long __high = __x >> _Nd_ull;
if (__high != 0) {
constexpr int __diff = (2 * _Nd_ull) - _Nd;
return __builtin_clzll(__high) - __diff;
}
constexpr auto __max_ull = numeric_limits<unsigned long long>::max();
unsigned long long __low = __x & __max_ull;
return (_Nd - _Nd_ull) + __builtin_clzll(__low);
}
}
template <typename _Tp> constexpr int __countr_zero(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
if (__x == 0) return _Nd;
constexpr auto _Nd_ull = numeric_limits<unsigned long long>::digits;
constexpr auto _Nd_ul = numeric_limits<unsigned long>::digits;
constexpr auto _Nd_u = numeric_limits<unsigned>::digits;
if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
return __builtin_ctz(__x);
else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul)
return __builtin_ctzl(__x);
else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull)
return __builtin_ctzll(__x);
else // (_Nd > _Nd_ull)
{
static_assert(_Nd <= (2 * _Nd_ull),
"Maximum supported integer size is 128-bit");
constexpr auto __max_ull = numeric_limits<unsigned long long>::max();
unsigned long long __low = __x & __max_ull;
if (__low != 0) return __builtin_ctzll(__low);
unsigned long long __high = __x >> _Nd_ull;
return __builtin_ctzll(__high) + _Nd_ull;
}
}
template <typename _Tp> constexpr int __popcount(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
if (__x == 0) return 0;
constexpr auto _Nd_ull = numeric_limits<unsigned long long>::digits;
constexpr auto _Nd_ul = numeric_limits<unsigned long>::digits;
constexpr auto _Nd_u = numeric_limits<unsigned>::digits;
if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_u)
return __builtin_popcount(__x);
else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ul)
return __builtin_popcountl(__x);
else if _GLIBCXX17_CONSTEXPR (_Nd <= _Nd_ull)
return __builtin_popcountll(__x);
else // (_Nd > _Nd_ull)
{
static_assert(_Nd <= (2 * _Nd_ull),
"Maximum supported integer size is 128-bit");
constexpr auto __max_ull = numeric_limits<unsigned long long>::max();
unsigned long long __low = __x & __max_ull;
unsigned long long __high = __x >> _Nd_ull;
return __builtin_popcountll(__low) + __builtin_popcountll(__high);
}
}
template <typename _Tp> constexpr _Tp __bit_ceil(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
if (__x == 0 || __x == 1) return 1;
auto __shift_exponent = _Nd - __countl_zero((_Tp)(__x - 1u));
#ifdef _GLIBCXX_HAVE_BUILTIN_IS_CONSTANT_EVALUATED
if (!__builtin_is_constant_evaluated()) {
__glibcxx_assert(__shift_exponent != numeric_limits<_Tp>::digits);
}
#endif
using __promoted_type = decltype(__x << 1);
if _GLIBCXX17_CONSTEXPR (!is_same<__promoted_type, _Tp>::value) {
const int __extra_exp = sizeof(__promoted_type) / sizeof(_Tp) / 2;
__shift_exponent |= (__shift_exponent & _Nd) << __extra_exp;
}
return (_Tp)1u << __shift_exponent;
}
template <typename _Tp> constexpr _Tp __bit_floor(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
if (__x == 0) return 0;
return (_Tp)1u << (_Nd - __countl_zero((_Tp)(__x >> 1)));
}
template <typename _Tp> constexpr _Tp __bit_width(_Tp __x) noexcept {
constexpr auto _Nd = numeric_limits<_Tp>::digits;
return _Nd - __countl_zero(__x);
}
} // namespace std
#endif
#endif
#line 2 "Library\\lib\\limits"
#line 4 "Library\\lib\\limits"
namespace workspace {
template <class _Tp> struct numeric_limits : std::numeric_limits<_Tp> {};
#ifdef __SIZEOF_INT128__
template <> struct numeric_limits<__uint128_t> {
constexpr static __uint128_t max() { return ~__uint128_t(0); }
constexpr static __uint128_t min() { return 0; }
};
template <> struct numeric_limits<__int128_t> {
constexpr static __int128_t max() {
return numeric_limits<__uint128_t>::max() >> 1;
}
constexpr static __int128_t min() { return -max() - 1; }
};
#endif
} // namespace workspace
#line 13 "Library\\lib\\alias"
namespace workspace {
constexpr static char eol = '\n';
using namespace std;
using i32 = int_least32_t;
using u32 = uint_least32_t;
using i64 = int_least64_t;
using u64 = uint_least64_t;
#ifdef __SIZEOF_INT128__
using i128 = __int128_t;
using u128 = __uint128_t;
#else
#warning 128-bit integer is not available.
#endif
template <class _T1, class _T2,
typename = decltype(std::declval<const _T2 &>() <
std::declval<const _T1 &>())>
constexpr
typename std::conditional<std::is_same<_T1, _T2>::value, const _T1 &,
typename std::common_type<_T1, _T2>::type>::type
min(const _T1 &__x, const _T2 &__y) noexcept {
return __y < __x ? __y : __x;
}
template <class _T1, class _T2, class _Compare,
typename = decltype(std::declval<_Compare>()(
std::declval<const _T2 &>(), std::declval<const _T1 &>()))>
constexpr
typename std::conditional<std::is_same<_T1, _T2>::value, const _T1 &,
typename std::common_type<_T1, _T2>::type>::type
min(const _T1 &__x, const _T2 &__y, _Compare __comp) noexcept {
return __comp(__y, __x) ? __y : __x;
}
template <class _Tp, typename = decltype(std::declval<const _Tp &>() <
std::declval<const _Tp &>())>
constexpr _Tp min(std::initializer_list<_Tp> __x) noexcept {
return *std::min_element(__x.begin(), __x.end());
}
template <class _Tp, class _Compare,
typename = decltype(std::declval<_Compare>()(
std::declval<const _Tp &>(), std::declval<const _Tp &>()))>
constexpr _Tp min(std::initializer_list<_Tp> __x, _Compare __comp) noexcept {
return *std::min_element(__x.begin(), __x.end(), __comp);
}
template <class _T1, class _T2,
typename = decltype(std::declval<const _T1 &>() <
std::declval<const _T2 &>())>
constexpr
typename std::conditional<std::is_same<_T1, _T2>::value, const _T1 &,
typename std::common_type<_T1, _T2>::type>::type
max(const _T1 &__x, const _T2 &__y) noexcept {
return __x < __y ? __y : __x;
}
template <class _T1, class _T2, class _Compare,
typename = decltype(std::declval<_Compare>()(
std::declval<const _T1 &>(), std::declval<const _T2 &>()))>
constexpr
typename std::conditional<std::is_same<_T1, _T2>::value, const _T1 &,
typename std::common_type<_T1, _T2>::type>::type
max(const _T1 &__x, const _T2 &__y, _Compare __comp) noexcept {
return __comp(__x, __y) ? __y : __x;
}
template <class _Tp, typename = decltype(std::declval<const _Tp &>() <
std::declval<const _Tp &>())>
constexpr _Tp max(std::initializer_list<_Tp> __x) noexcept {
return *std::max_element(__x.begin(), __x.end());
}
template <class _Tp, class _Compare,
typename = decltype(std::declval<_Compare>()(
std::declval<const _Tp &>(), std::declval<const _Tp &>()))>
constexpr _Tp max(std::initializer_list<_Tp> __x, _Compare __comp) noexcept {
return *std::max_element(__x.begin(), __x.end(), __comp);
}
#ifdef _GLIBCXX_BIT
template <typename _Tp> constexpr _Tp __bsf(_Tp __x) noexcept {
return std::__countr_zero(__x);
}
template <typename _Tp> constexpr _Tp __bsr(_Tp __x) noexcept {
return std::__bit_width(__x) - 1;
}
#endif
} // namespace workspace
#line 6 "other-workspace\\y.cc"
// #include "lib/cxx20"
#line 1 "Library\\lib\\direct"
#ifdef ONLINE_JUDGE
#pragma GCC optimize("O3")
#pragma GCC target("avx,avx2")
#pragma GCC optimize("unroll-loops")
#endif
#line 8 "other-workspace\\y.cc"
// #include "lib/opt"
#line 2 "Library\\src\\sys\\call_once.hpp"
/**
* @file call_once.hpp
* @brief Call Once
*/
#line 9 "Library\\src\\sys\\call_once.hpp"
namespace workspace {
/**
* @brief Call once.
*/
template <class _F> void call_once(_F &&__f) {
static std::unordered_set<void *> __called;
if (__called.count(std::addressof(__f))) return;
__called.emplace(std::addressof(__f));
__f();
}
} // namespace workspace
#line 2 "Library\\src\\sys\\clock.hpp"
/**
* @file clock.hpp
* @brief Clock
*/
#line 9 "Library\\src\\sys\\clock.hpp"
namespace workspace {
using namespace std::chrono;
namespace internal {
// The start time of the program.
const auto start_time{system_clock::now()};
} // namespace internal
/**
* @return Elapsed time of the program.
*/
decltype(auto) elapsed() noexcept {
const auto end_time{system_clock::now()};
return duration_cast<milliseconds>(end_time - internal::start_time).count();
}
} // namespace workspace
#line 2 "Library\\src\\sys\\ejection.hpp"
/**
* @file ejection.hpp
* @brief Ejection
*/
#line 9 "Library\\src\\sys\\ejection.hpp"
namespace workspace {
namespace internal {
struct ejection {
bool exit = 0;
};
} // namespace internal
/**
* @brief eject from a try block, throw nullptr
* @param arg output
*/
template <class Tp> void eject(Tp const &arg) {
std::cout << arg << "\n";
throw internal::ejection{};
}
void exit() { throw internal::ejection{true}; }
} // namespace workspace
#line 2 "Library\\src\\sys\\iteration.hpp"
/**
* @file iteration.hpp
* @brief Case Iteration
*/
#line 9 "Library\\src\\sys\\iteration.hpp"
#line 11 "Library\\src\\sys\\iteration.hpp"
namespace workspace {
void main();
struct {
// 1-indexed
unsigned current{0};
unsigned total{1};
void read() { (std::cin >> total).ignore(); }
int iterate() {
static bool once = false;
assert(!once);
once = true;
while (current++ < total) {
try {
main();
} catch (internal::ejection const& status) {
if (status.exit) break;
}
}
return 0;
}
} case_info;
} // namespace workspace
#line 2 "Library\\lib\\utils"
// #include "src/utils/cached.hpp"
#line 2 "Library\\src\\utils\\cat.hpp"
/**
* @file cat.hpp
* @brief Cat
*/
#line 9 "Library\\src\\utils\\cat.hpp"
#line 2 "Library\\lib\\cxx17"
#ifndef _CXX17_CONSTEXPR
#if __cplusplus >= 201703L
#define _CXX17_CONSTEXPR constexpr
#else
#define _CXX17_CONSTEXPR
#endif
#endif
#if __cplusplus < 201703L
namespace std {
/**
* @brief Return the size of a container.
* @param __cont Container.
*/
template <typename _Container>
constexpr auto size(const _Container& __cont) noexcept(noexcept(__cont.size()))
-> decltype(__cont.size()) {
return __cont.size();
}
/**
* @brief Return the size of an array.
*/
template <typename _Tp, size_t _Nm>
constexpr size_t size(const _Tp (&)[_Nm]) noexcept {
return _Nm;
}
} // namespace std
#endif
#line 11 "Library\\src\\utils\\cat.hpp"
namespace workspace {
/**
* @brief Concatenate two sequences.
*
* @param __c1
* @param __c2
* @return Concatenated sequence.
*/
template <class _C1, class _C2>
constexpr decltype(auto) cat(_C1 &&__c1, _C2 &&__c2) noexcept {
auto __c = std::forward<_C1>(__c1);
if _CXX17_CONSTEXPR (std::is_rvalue_reference<decltype(__c2)>::value)
__c.insert(std::end(__c), std::make_move_iterator(std::begin(__c2)),
std::make_move_iterator(std::end(__c2)));
else
__c.insert(std::end(__c), std::cbegin(__c2), std::cend(__c2));
return __c;
}
/**
* @return Concatenated sequence.
*/
template <class _C1, class _C2, class... _Args>
constexpr decltype(auto) cat(_C1 &&__c1, _C2 &&__c2,
_Args &&...__args) noexcept {
return cat(cat(std::forward<_C1>(__c1), std::forward<_C2>(__c2)),
std::forward<_Args>(__args)...);
}
} // namespace workspace
#line 2 "Library\\src\\utils\\chval.hpp"
/**
* @file chval.hpp
* @brief Change Less/Greater
*/
#line 9 "Library\\src\\utils\\chval.hpp"
namespace workspace {
/**
* @brief Substitute __y for __x if __y < __x.
* @param __x Reference
* @param __y Comparison target
* @return Whether or not __x is updated.
*/
template <class _T1, class _T2,
typename = decltype(std::declval<_T2>() < std::declval<_T1 &>())>
typename std::enable_if<std::is_assignable<_T1 &, _T2>::value, bool>::type chle(
_T1 &__x, _T2 &&__y) noexcept {
return __y < __x ? __x = std::forward<_T2>(__y), true : false;
}
/**
* @brief Substitute __y for __x if __x < __y.
* @param __x Reference
* @param __y Comparison target
* @return Whether or not __x is updated.
*/
template <class _T1, class _T2,
typename = decltype(std::declval<_T1 &>() < std::declval<_T2>())>
typename std::enable_if<std::is_assignable<_T1 &, _T2>::value, bool>::type chgr(
_T1 &__x, _T2 &&__y) noexcept {
return __x < __y ? __x = std::forward<_T2>(__y), true : false;
}
/**
* @brief Substitute __y for __x if __comp(__y, __x) is true.
* @param __x Reference
* @param __y Comparison target
* @param __comp Compare function object
* @return Whether or not __x is updated.
*/
template <class _T1, class _T2, class _Compare,
typename = decltype(std::declval<_Compare>()(std::declval<_T2>(),
std::declval<_T1 &>()))>
typename std::enable_if<std::is_assignable<_T1 &, _T2>::value, bool>::type chle(
_T1 &__x, _T2 &&__y, _Compare __comp) noexcept {
return __comp(__y, __x) ? __x = std::forward<_T2>(__y), true : false;
}
/**
* @brief Substitute __y for __x if __comp(__x, __y) is true.
* @param __x Reference
* @param __y Comparison target
* @param __comp Compare function object
* @return Whether or not __x is updated.
*/
template <class _T1, class _T2, class _Compare,
typename = decltype(std::declval<_Compare>()(std::declval<_T1 &>(),
std::declval<_T2>()))>
typename std::enable_if<std::is_assignable<_T1 &, _T2>::value, bool>::type chgr(
_T1 &__x, _T2 &&__y, _Compare __comp) noexcept {
return __comp(__x, __y) ? __x = std::forward<_T2>(__y), true : false;
}
} // namespace workspace
#line 1 "Library\\src\\utils\\compare.hpp"
/**
* @file compare.hpp
* @brief Compare
*/
#line 2 "Library\\src\\utils\\sfinae.hpp"
/**
* @file sfinae.hpp
* @brief SFINAE
*/
#line 10 "Library\\src\\utils\\sfinae.hpp"
#include <type_traits>
#ifndef __INT128_DEFINED__
#ifdef __SIZEOF_INT128__
#define __INT128_DEFINED__ 1
#else
#define __INT128_DEFINED__ 0
#endif
#endif
namespace std {
#if __INT128_DEFINED__
template <> struct make_signed<__uint128_t> { using type = __int128_t; };
template <> struct make_signed<__int128_t> { using type = __int128_t; };
template <> struct make_unsigned<__uint128_t> { using type = __uint128_t; };
template <> struct make_unsigned<__int128_t> { using type = __uint128_t; };
template <> struct is_signed<__uint128_t> : std::false_type {};
template <> struct is_signed<__int128_t> : std::true_type {};
template <> struct is_unsigned<__uint128_t> : std::true_type {};
template <> struct is_unsigned<__int128_t> : std::false_type {};
#endif
} // namespace std
namespace workspace {
template <class Tp, class... Args> struct variadic_front { using type = Tp; };
template <class... Args> struct variadic_back;
template <class Tp> struct variadic_back<Tp> { using type = Tp; };
template <class Tp, class... Args> struct variadic_back<Tp, Args...> {
using type = typename variadic_back<Args...>::type;
};
template <class type, template <class> class trait>
using enable_if_trait_type = typename std::enable_if<trait<type>::value>::type;
/**
* @brief Return type of subscripting ( @c [] ) access.
*/
template <class _Tp>
using subscripted_type =
typename std::decay<decltype(std::declval<_Tp&>()[0])>::type;
template <class Container>
using element_type = typename std::decay<decltype(
*std::begin(std::declval<Container&>()))>::type;
template <class _Tp, class = std::nullptr_t>
struct has_begin : std::false_type {};
template <class _Tp>
struct has_begin<_Tp, decltype(std::begin(std::declval<_Tp>()), nullptr)>
: std::true_type {};
template <class _Tp, class = void> struct has_mod : std::false_type {};
template <class _Tp>
struct has_mod<_Tp, std::__void_t<decltype(_Tp::mod)>> : std::true_type {};
template <class _Tp, class = void> struct is_integral_ext : std::false_type {};
template <class _Tp>
struct is_integral_ext<
_Tp, typename std::enable_if<std::is_integral<_Tp>::value>::type>
: std::true_type {};
#if __INT128_DEFINED__
template <> struct is_integral_ext<__int128_t> : std::true_type {};
template <> struct is_integral_ext<__uint128_t> : std::true_type {};
#endif
#if __cplusplus >= 201402
template <class _Tp>
constexpr static bool is_integral_ext_v = is_integral_ext<_Tp>::value;
#endif
template <typename _Tp, typename = void> struct multiplicable_uint {
using type = uint_least32_t;
};
template <typename _Tp>
struct multiplicable_uint<
_Tp,
typename std::enable_if<(2 < sizeof(_Tp)) &&
(!__INT128_DEFINED__ || sizeof(_Tp) <= 4)>::type> {
using type = uint_least64_t;
};
#if __INT128_DEFINED__
template <typename _Tp>
struct multiplicable_uint<_Tp,
typename std::enable_if<(4 < sizeof(_Tp))>::type> {
using type = __uint128_t;
};
#endif
template <typename _Tp> struct multiplicable_int {
using type =
typename std::make_signed<typename multiplicable_uint<_Tp>::type>::type;
};
template <typename _Tp> struct multiplicable {
using type = std::conditional_t<
is_integral_ext<_Tp>::value,
std::conditional_t<std::is_signed<_Tp>::value,
typename multiplicable_int<_Tp>::type,
typename multiplicable_uint<_Tp>::type>,
_Tp>;
};
template <class> struct first_arg { using type = void; };
template <class _R, class _Tp, class... _Args>
struct first_arg<_R(_Tp, _Args...)> {
using type = _Tp;
};
template <class _R, class _Tp, class... _Args>
struct first_arg<_R (*)(_Tp, _Args...)> {
using type = _Tp;
};
template <class _G, class _R, class _Tp, class... _Args>
struct first_arg<_R (_G::*)(_Tp, _Args...)> {
using type = _Tp;
};
template <class _G, class _R, class _Tp, class... _Args>
struct first_arg<_R (_G::*)(_Tp, _Args...) const> {
using type = _Tp;
};
template <class _Tp, class = void> struct parse_compare : first_arg<_Tp> {};
template <class _Tp>
struct parse_compare<_Tp, std::__void_t<decltype(&_Tp::operator())>>
: first_arg<decltype(&_Tp::operator())> {};
} // namespace workspace
#line 7 "Library\\src\\utils\\compare.hpp"
#if __cplusplus >= 201703L
namespace workspace {
/**
* @brief Compare 2 points by their value of `atan2`.
*
* @return
*/
template <class _Tp>
bool compare_arg(const _Tp& __p1, const _Tp& __p2) noexcept {
const auto& [__x1, __y1] = __p1;
const auto& [__x2, __y2] = __p2;
using value_type = std::decay_t<decltype(__x1)>;
using mul_type = typename multiplicable<value_type>::type;
if (__y1 == value_type(0))
return value_type(0) <= __x1 &&
(value_type(0) < __y2 ||
(__y2 == value_type(0) && __x2 < value_type(0)));
return value_type(0) < __y1
? value_type(0) <= __y2 &&
mul_type(__y1) * __x2 < mul_type(__x1) * __y2
: value_type(0) <= __y2 ||
mul_type(__y1) * __x2 < mul_type(__x1) * __y2;
}
} // namespace workspace
#endif
#line 6 "Library\\lib\\utils"
// #include "src/utils/fixed_point.hpp"
// #include "src/utils/hash.hpp"
#line 2 "Library\\src\\utils\\io\\istream.hpp"
/**
* @file istream.hpp
* @brief Input Stream
*/
#include <cxxabi.h>
#line 13 "Library\\src\\utils\\io\\istream.hpp"
#line 16 "Library\\src\\utils\\io\\istream.hpp"
namespace workspace {
namespace _istream_impl {
template <class _Tp, typename = void> struct helper {
helper(std::istream &__is, _Tp &__x) {
if _CXX17_CONSTEXPR (has_begin<_Tp &>::value)
for (auto &&__e : __x) helper<std::decay_t<decltype(__e)>>(__is, __e);
else
static_assert(has_begin<_Tp>::value, "istream unsupported type.");
}
};
template <class _Tp>
struct helper<_Tp, std::__void_t<decltype(std::declval<std::istream &>() >>
std::declval<_Tp &>())>> {
helper(std::istream &__is, _Tp &__x) { __is >> __x; }
};
#ifdef __SIZEOF_INT128__
template <> struct helper<__uint128_t, void> {
helper(std::istream &__is, __uint128_t &__x) {
std::string __s;
__is >> __s;
bool __neg = false;
if (__s.front() == '-') __neg = true, __s.erase(__s.begin());
__x = 0;
for (char __d : __s) {
__x *= 10;
__d -= '0';
if (__neg)
__x -= __d;
else
__x += __d;
}
}
};
template <> struct helper<__int128_t, void> {
helper(std::istream &__is, __int128_t &__x) {
std::string __s;
__is >> __s;
bool __neg = false;
if (__s.front() == '-') __neg = true, __s.erase(__s.begin());
__x = 0;
for (char __d : __s) {
__x *= 10;
__d -= '0';
if (__neg)
__x -= __d;
else
__x += __d;
}
}
};
#endif // INT128
template <class _T1, class _T2> struct helper<std::pair<_T1, _T2>> {
helper(std::istream &__is, std::pair<_T1, _T2> &__x) {
helper<_T1>(__is, __x.first), helper<_T2>(__is, __x.second);
}
};
template <class... _Tp> struct helper<std::tuple<_Tp...>> {
helper(std::istream &__is, std::tuple<_Tp...> &__x) { iterate(__is, __x); }
private:
template <class _Tuple, size_t _Nm = 0>
void iterate(std::istream &__is, _Tuple &__x) {
if _CXX17_CONSTEXPR (_Nm != std::tuple_size<_Tuple>::value) {
helper<typename std::tuple_element<_Nm, _Tuple>::type>(
__is, std::get<_Nm>(__x)),
iterate<_Tuple, _Nm + 1>(__is, __x);
}
}
};
} // namespace _istream_impl
/**
* @brief A wrapper class for std::istream.
*/
class istream : public std::istream {
public:
/**
* @brief Wrapped operator.
*/
template <typename _Tp> istream &operator>>(_Tp &__x) {
_istream_impl::helper<_Tp>(*this, __x);
if (std::istream::fail()) {
static auto once = atexit([] {
std::cerr << "\n\033[43m\033[30mwarning: failed to read \'"
<< abi::__cxa_demangle(typeid(_Tp).name(), 0, 0, 0)
<< "\'.\033[0m\n\n";
});
assert(!once);
}
return *this;
}
};
decltype(auto) cin = static_cast<istream &>(std::cin);
} // namespace workspace
#line 9 "Library\\lib\\utils"
// #include "src/utils/io/ostream.hpp"
// #include "src/utils/io/read.hpp"
#line 2 "Library\\src\\utils\\grid\\motion.hpp"
/**
* @file motion.hpp
* @brief Motion
*/
#line 9 "Library\\src\\utils\\grid\\motion.hpp"
#line 11 "Library\\src\\utils\\grid\\motion.hpp"
namespace workspace {
/**
* @brief Transpose.
* @param __grid
*/
template <class _Grid,
typename = decltype(std::declval<std::decay_t<_Grid>>()[0].resize(0))>
constexpr decltype(auto) transpose(_Grid &&__grid) noexcept {
#if __cplusplus < 201703L
auto __h = __grid.size(), __w = __grid[0].size();
#else
auto __h = std::size(__grid), __w = std::size(__grid[0]);
#endif
std::decay_t<_Grid> __t(__w);
for (auto &&__r : __t) __r.resize(__h);
for (size_t __i = 0; __i != __h; ++__i)
for (size_t __j = 0; __j != __w; ++__j)
if _CXX17_CONSTEXPR (std::is_rvalue_reference<decltype(__grid)>::value)
__t[__j][__i] = std::move(__grid[__i][__j]);
else
__t[__j][__i] = __grid[__i][__j];
return __t;
}
/**
* @brief Transpose.
* @param __grid
*/
template <class _Tp, size_t _Rows, size_t _Cols>
constexpr decltype(auto) transpose(const _Tp (&__grid)[_Rows][_Cols]) noexcept {
std::array<std::array<_Tp, _Rows>, _Cols> __t;
for (size_t __i = 0; __i != _Rows; ++__i)
for (size_t __j = 0; __j != _Cols; ++__j) __t[__j][__i] = __grid[__i][__j];
return __t;
}
/**
* @brief Transpose.
* @param __grid
*/
template <class _Tp, size_t _Rows, size_t _Cols>
constexpr decltype(auto) transpose(_Tp(&&__grid)[_Rows][_Cols]) noexcept {
std::array<std::array<_Tp, _Rows>, _Cols> __t;
for (size_t __i = 0; __i != _Rows; ++__i)
for (size_t __j = 0; __j != _Cols; ++__j)
__t[__j][__i] = std::move(__grid[__i][__j]);
return __t;
}
/**
* @brief Transpose.
* @param __grid
*/
template <class _Tp, size_t _Rows, size_t _Cols>
constexpr decltype(auto) transpose(
const std::array<std::array<_Tp, _Cols>, _Rows> &__grid) noexcept {
std::array<std::array<_Tp, _Rows>, _Cols> __t;
for (size_t __i = 0; __i != _Rows; ++__i)
for (size_t __j = 0; __j != _Cols; ++__j) __t[__j][__i] = __grid[__i][__j];
return __t;
}
/**
* @brief Transpose.
* @param __grid
*/
template <class _Tp, size_t _Rows, size_t _Cols>
constexpr decltype(auto) transpose(
std::array<std::array<_Tp, _Cols>, _Rows> &&__grid) noexcept {
std::array<std::array<_Tp, _Rows>, _Cols> __t;
for (size_t __i = 0; __i != _Rows; ++__i)
for (size_t __j = 0; __j != _Cols; ++__j)
__t[__j][__i] = std::move(__grid[__i][__j]);
return __t;
}
/**
* @brief Roll the grid counter-clockwise.
* @param __grid
*/
template <class _Grid> decltype(auto) roll_ccw(_Grid &&__grid) noexcept {
if _CXX17_CONSTEXPR (std::is_rvalue_reference<decltype(__grid)>::value) {
auto __t = transpose(std::move(__grid));
std::reverse(std::begin(__t), std::end(__t));
return __t;
} else {
auto __t = transpose(__grid);
std::reverse(std::begin(__t), std::end(__t));
return __t;
}
}
/**
* @brief Roll the grid clockwise.
* @param __grid
*/
template <class _Grid> decltype(auto) roll_cw(_Grid &&__grid) noexcept {
if _CXX17_CONSTEXPR (std::is_rvalue_reference<decltype(__grid)>::value) {
std::reverse(std::begin(__grid), std::end(__grid));
return transpose(std::move(__grid));
} else {
auto __t = transpose(__grid);
for (auto &&__r : __t) std::reverse(std::begin(__r), std::end(__r));
return __t;
}
}
} // namespace workspace
#line 2 "Library\\src\\utils\\io\\setup.hpp"
/**
* @file setup.hpp
* @brief I/O Setup
*/
#line 10 "Library\\src\\utils\\io\\setup.hpp"
namespace workspace {
/**
* @brief Setup I/O.
* @param __n Standard output precision
*/
void io_setup(int __n) {
std::cin.tie(0)->sync_with_stdio(0);
std::cout << std::fixed << std::setprecision(__n);
#ifdef _buffer_check
atexit([] {
char bufc;
if (std::cin >> bufc)
std::cerr << "\n\033[43m\033[30mwarning: buffer not empty.\033[0m\n\n";
});
#endif
}
} // namespace workspace
#line 2 "Library\\src\\utils\\iterator\\category.hpp"
/*
* @file category.hpp
* @brief Iterator Category
*/
#line 10 "Library\\src\\utils\\iterator\\category.hpp"
namespace workspace {
/*
* @tparam Tuple Tuple of iterator types
*/
template <class Tuple, size_t N = std::tuple_size<Tuple>::value - 1>
struct common_iterator_category {
using type = typename std::common_type<
typename common_iterator_category<Tuple, N - 1>::type,
typename std::iterator_traits<typename std::tuple_element<
N, Tuple>::type>::iterator_category>::type;
};
template <class Tuple> struct common_iterator_category<Tuple, 0> {
using type = typename std::iterator_traits<
typename std::tuple_element<0, Tuple>::type>::iterator_category;
};
} // namespace workspace
#line 2 "Library\\src\\utils\\iterator\\reverse.hpp"
/*
* @file reverse_iterator.hpp
* @brief Reverse Iterator
*/
#if __cplusplus >= 201703L
#include <iterator>
#include <optional>
namespace workspace {
/*
* @class reverse_iterator
* @brief Wrapper class for `std::reverse_iterator`.
* @see http://gcc.gnu.org/PR51823
*/
template <class Iterator>
class reverse_iterator : public std::reverse_iterator<Iterator> {
using base_std = std::reverse_iterator<Iterator>;
std::optional<typename base_std::value_type> deref;
public:
using base_std::reverse_iterator;
constexpr typename base_std::reference operator*() noexcept {
if (!deref) {
Iterator tmp = base_std::current;
deref = *--tmp;
}
return deref.value();
}
constexpr reverse_iterator &operator++() noexcept {
base_std::operator++();
deref.reset();
return *this;
}
constexpr reverse_iterator &operator--() noexcept {
base_std::operator++();
deref.reset();
return *this;
}
constexpr reverse_iterator operator++(int) noexcept {
base_std::operator++();
deref.reset();
return *this;
}
constexpr reverse_iterator operator--(int) noexcept {
base_std::operator++();
deref.reset();
return *this;
}
};
} // namespace workspace
#endif
#line 2 "Library\\src\\utils\\make_vector.hpp"
/**
* @file make_vector.hpp
* @brief Multi-dimensional Vector
*/
#if __cplusplus >= 201703L
#include <tuple>
#include <vector>
namespace workspace {
/**
* @brief Make a multi-dimensional vector.
*
* @param __dim Dimension
* @param __x Initial value
*/
template <typename _Tp, class _Dim, size_t _Nm>
constexpr decltype(auto) make_vector([[maybe_unused]] _Dim* __dim,
const _Tp& __x = _Tp()) {
static_assert(std::is_convertible<_Dim, size_t>::value);
if constexpr (_Nm)
return std::vector(*__dim,
make_vector<_Tp, _Dim, _Nm - 1>(std::next(__dim), __x));
else
return __x;
}
/**
* @brief Make a multi-dimensional vector.
*
* @param __dim Dimension
* @param __x Initial value
*/
template <typename _Tp, class _Dim, size_t _Nm>
constexpr decltype(auto) make_vector(const _Dim (&__dim)[_Nm],
const _Tp& __x = _Tp()) {
return make_vector<_Tp, _Dim, _Nm>((_Dim*)__dim, __x);
}
/**
* @brief Make a multi-dimensional vector.
*
* @param __dim Dimension
* @param __x Initial value
*/
template <typename _Tp, class _Dim, size_t _Nm = 0>
constexpr decltype(auto) make_vector([[maybe_unused]] const _Dim& __dim,
const _Tp& __x = _Tp()) {
if constexpr (_Nm == std::tuple_size<_Dim>::value)
return __x;
else {
static_assert(
std::is_convertible<std::tuple_element_t<_Nm, _Dim>, size_t>::value);
return std::vector(std::get<_Nm>(__dim),
make_vector<_Tp, _Dim, _Nm + 1>(__dim, __x));
}
}
} // namespace workspace
#endif
#line 16 "Library\\lib\\utils"
// #include "src/utils/py-like/enumerate.hpp"
#line 2 "Library\\src\\utils\\py-like\\range.hpp"
/**
* @file range.hpp
* @brief Range
*/
#line 9 "Library\\src\\utils\\py-like\\range.hpp"
#line 2 "Library\\src\\utils\\py-like\\reversed.hpp"
/**
* @file reversed.hpp
* @brief Reversed
*/
#include <initializer_list>
#line 10 "Library\\src\\utils\\py-like\\reversed.hpp"
namespace workspace {
namespace _reversed_impl {
template <class _Container> class reversed {
_Container __cont;
public:
constexpr reversed(_Container &&__cont) noexcept : __cont(__cont) {}
constexpr decltype(auto) begin() noexcept { return std::rbegin(__cont); }
constexpr decltype(auto) begin() const noexcept {
return std::rbegin(__cont);
}
constexpr decltype(auto) end() noexcept { return std::rend(__cont); }
constexpr decltype(auto) end() const noexcept { return std::rend(__cont); }
constexpr decltype(auto) size() const noexcept {
return
#if __cplusplus < 201703L
__cont.size();
#else
std::size(__cont);
#endif
}
};
} // namespace _reversed_impl
template <class _Container>
constexpr decltype(auto) reversed(_Container &&__cont) noexcept {
return _reversed_impl::reversed<_Container>{std::forward<_Container>(__cont)};
}
template <class _Tp>
constexpr decltype(auto) reversed(
std::initializer_list<_Tp> &&__cont) noexcept {
return _reversed_impl::reversed<std::initializer_list<_Tp>>{
std::forward<std::initializer_list<_Tp>>(__cont)};
}
} // namespace workspace
#line 12 "Library\\src\\utils\\py-like\\range.hpp"
#if __cplusplus >= 201703L
namespace workspace {
template <class _Index> class range {
_Index __first, __last;
public:
class iterator {
_Index current;
public:
using difference_type = std::ptrdiff_t;
using value_type = _Index;
using reference = typename std::add_const<_Index>::type &;
using pointer = iterator;
using iterator_category = std::random_access_iterator_tag;
constexpr iterator(const _Index &__i = _Index()) noexcept : current(__i) {}
constexpr bool operator==(const iterator &__x) const noexcept {
return current == __x.current;
}
constexpr bool operator!=(const iterator &__x) const noexcept {
return current != __x.current;
}
constexpr bool operator<(const iterator &__x) const noexcept {
return current < __x.current;
}
constexpr bool operator<=(const iterator &__x) const noexcept {
return current <= __x.current;
}
constexpr bool operator>(const iterator &__x) const noexcept {
return current > __x.current;
}
constexpr bool operator>=(const iterator &__x) const noexcept {
return current >= __x.current;
}
constexpr iterator &operator++() noexcept {
++current;
return *this;
}
constexpr iterator &operator++(int) noexcept {
auto __tmp = *this;
++current;
return __tmp;
}
constexpr iterator &operator--() noexcept {
--current;
return *this;
}
constexpr iterator &operator--(int) noexcept {
auto __tmp = *this;
--current;
return __tmp;
}
constexpr difference_type operator-(const iterator &__x) const noexcept {
return current - __x.current;
}
constexpr iterator &operator+=(difference_type __x) noexcept {
current += __x;
return *this;
}
constexpr iterator operator+(difference_type __x) const noexcept {
return iterator(*this) += __x;
}
constexpr iterator &operator-=(difference_type __x) noexcept {
current -= __x;
return *this;
}
constexpr iterator operator-(difference_type __x) const noexcept {
return iterator(*this) -= __x;
}
constexpr reference operator*() const noexcept { return current; }
};
constexpr range(_Index __first, _Index __last) noexcept
: __first(__first), __last(__last) {}
constexpr range(_Index __last) noexcept : __first(), __last(__last) {}
constexpr iterator begin() const noexcept { return iterator{__first}; }
constexpr iterator end() const noexcept { return iterator{__last}; }
constexpr reverse_iterator<iterator> rbegin() const noexcept {
return reverse_iterator<iterator>(end());
}
constexpr reverse_iterator<iterator> rend() const noexcept {
return reverse_iterator<iterator>(begin());
}
constexpr size_t size() const noexcept {
return std::distance(__first, __last);
}
};
template <class... _Args>
constexpr decltype(auto) rrange(_Args &&...__args) noexcept {
return reversed(range(std::forward<_Args>(__args)...));
}
template <class _Container>
constexpr decltype(auto) iterate(_Container &&__cont) noexcept {
return range(std::begin(__cont), std::end(__cont));
}
template <class _Container>
constexpr decltype(auto) riterate(_Container &&__cont) noexcept {
return range(std::rbegin(__cont), std::rend(__cont));
}
} // namespace workspace
#endif
#line 18 "Library\\lib\\utils"
// #include "src/utils/py-like/reversed.hpp"
// #include "src/utils/py-like/zip.hpp"
#line 2 "Library\\src\\utils\\rand\\rng.hpp"
/**
* @file rng.hpp
* @brief Random Number Generator
*/
#line 9 "Library\\src\\utils\\rand\\rng.hpp"
namespace workspace {
template <typename _Arithmetic>
using uniform_distribution = typename std::conditional<
std::is_integral<_Arithmetic>::value,
std::uniform_int_distribution<_Arithmetic>,
std::uniform_real_distribution<_Arithmetic>>::type;
template <typename _Arithmetic, class _Engine = std::mt19937>
class random_number_generator : uniform_distribution<_Arithmetic> {
using base = uniform_distribution<_Arithmetic>;
_Engine __engine;
public:
random_number_generator(_Arithmetic __min, _Arithmetic __max)
: base(__min, __max), __engine(std::random_device{}()) {}
random_number_generator(_Arithmetic __max = 1)
: random_number_generator(0, __max) {}
random_number_generator(typename base::param_type const& __param)
: base(__param), __engine(std::random_device{}()) {}
decltype(auto) operator()() noexcept { return base::operator()(__engine); }
};
} // namespace workspace
#line 2 "Library\\src\\utils\\rand\\shuffle.hpp"
/**
* @file shuffle.hpp
* @brief Shuffle
*/
#line 10 "Library\\src\\utils\\rand\\shuffle.hpp"
namespace workspace {
template <class _RAIter, class _Engine = std::mt19937>
void shuffle(_RAIter __first, _RAIter __last) {
static _Engine __engine(std::random_device{}());
std::shuffle(__first, __last, __engine);
}
} // namespace workspace
#line 2 "Library\\src\\utils\\round_div.hpp"
/*
* @file round_div.hpp
* @brief Round Integer Division
*/
#line 9 "Library\\src\\utils\\round_div.hpp"
#line 11 "Library\\src\\utils\\round_div.hpp"
namespace workspace {
/*
* @fn floor_div
* @brief floor of fraction.
* @param x the numerator
* @param y the denominator
* @return maximum integer z s.t. z <= x / y
* @note y must be nonzero.
*/
template <typename T1, typename T2>
constexpr typename std::enable_if<(is_integral_ext<T1>::value &&
is_integral_ext<T2>::value),
typename std::common_type<T1, T2>::type>::type
floor_div(T1 x, T2 y) {
assert(y != 0);
if (y < 0) x = -x, y = -y;
return x < 0 ? (x - y + 1) / y : x / y;
}
/*
* @fn ceil_div
* @brief ceil of fraction.
* @param x the numerator
* @param y the denominator
* @return minimum integer z s.t. z >= x / y
* @note y must be nonzero.
*/
template <typename T1, typename T2>
constexpr typename std::enable_if<(is_integral_ext<T1>::value &&
is_integral_ext<T2>::value),
typename std::common_type<T1, T2>::type>::type
ceil_div(T1 x, T2 y) {
assert(y != 0);
if (y < 0) x = -x, y = -y;
return x < 0 ? x / y : (x + y - 1) / y;
}
} // namespace workspace
#line 23 "Library\\lib\\utils"
// #include "src\utils\rand\tree.hpp"
// #include "src\utils\reference_list.hpp"
#line 11 "other-workspace\\y.cc"
signed main() {
using namespace workspace;
io_setup(15);
/* given
case_info.read(); //*/
/* unspecified
case_info.total = -1; //*/
return case_info.iterate();
}
#line 2 "Library\\src\\graph\\directed\\strongly_connected_components.hpp"
/**
* @file strongly_connected_component.hpp
* @brief Strongly Connected Component Algorithm
*/
#line 12 "Library\\src\\graph\\directed\\strongly_connected_components.hpp"
namespace workspace {
class strongly_connected_component {
public:
using size_type = std::size_t;
protected:
std::vector<std::vector<size_type>> __graph, __dag;
std::vector<size_type> __low;
bool made() const { return !__low.empty(); }
/**
* @param src Vertex
* @param c Counter
* @param ptr Pointer to a stack
* @param used Negative indexed
* @return Low-link number of the vertex.
*/
size_type affix(size_type src, size_type &c, size_type *&ptr,
bool *const used) {
if (__low[src]) return __low[src];
const size_type idx = ++c;
__low[src] = idx;
*ptr++ = src;
for (const size_type dst : __graph[src])
__low[src] = std::min(__low[src], affix(dst, c, ptr, used));
if (__low[src] == idx) {
__dag.push_back({});
const size_type ccnt = __dag.size();
used[-ccnt] = true;
size_type *srcp = ptr;
do __low[*--srcp] = -ccnt;
while (*srcp != src);
while (ptr != srcp) {
const size_type now = *--ptr;
for (const size_type dst : __graph[now]) {
if (!used[(int)__low[dst]]) {
__dag.back().emplace_back(__low[dst]);
used[(int)__low[dst]] = true;
}
}
}
for (const size_type dst : __dag.back()) used[dst] = false;
used[-ccnt] = false;
return idx;
}
return __low[src];
}
public:
strongly_connected_component() = default;
strongly_connected_component(size_type __n) : __graph(__n) {}
size_type add_node() {
__graph.emplace_back();
return __graph.size() - 1;
}
std::vector<size_type> add_nodes(size_type __n) {
std::vector<size_type> __nds(__n);
std::iota(__nds.begin(), __nds.end(), size());
__graph.resize(size() + __n);
return __nds;
}
/**
* @brief Add an edge.
* @param src Source
* @param dst Destination
*/
void add_edge(size_type src, size_type dst) {
assert(src < size());
assert(dst < size());
__graph[src].emplace_back(dst);
}
/**
* @return Number of components.
*/
size_type count() {
assert(made());
return __dag.size();
}
/**
* @return Number of vertices.
*/
size_type size() const { return __graph.size(); }
/**
* @param v Vertex
* @return Component including given vertex.
*/
size_type operator[](size_type v) {
assert(made());
return __low[v];
}
const auto &graph() const { return __graph; }
/**
* @return Directed Acyclic Graph consisting of components.
*/
const auto &shrinked_dag() {
assert(made());
return __dag;
}
/**
* @brief Run SCC decomposition in linear time.
*/
void make() {
__low.assign(size(), 0);
__dag.clear();
size_type *ptr = new size_type[size()];
bool *const used = new bool[size()];
for (size_type v{}, c{}; v != size(); ++v) affix(v, c, ptr, used + size());
delete[] ptr;
delete[] used;
for (auto &e : __low) e += __dag.size();
reverse(begin(__dag), end(__dag));
for (auto &arcs : __dag)
for (auto &dst : arcs) dst += __dag.size();
}
};
} // namespace workspace
#line 27 "other-workspace\\y.cc"
namespace workspace {
void main() {
// start here!
int n, m;
cin >> n >> m;
strongly_connected_component scc(n);
vector<vector<int>> ud(n);
while (m--) {
int a, b;
cin >> a >> b;
--a, --b;
ud[a].emplace_back(b);
ud[b].emplace_back(a);
scc.add_edge(a, b);
}
scc.make();
vector<int> checked(n);
vector<pair<i32, i32>> ans;
for (auto src : range(n)) {
if (checked[src]) continue;
queue<int> Q;
Q.emplace(src);
vector<int> seq;
while (!Q.empty()) {
src = Q.front();
Q.pop();
if (checked[src]) {
continue;
}
seq.emplace_back(src);
checked[src] = 1;
for (auto &&to : ud[src]) {
Q.emplace(to);
}
}
sort(begin(seq), end(seq), [&](auto u, auto v) { return scc[u] < scc[v]; });
for (auto i : iterate(seq)) {
if (i != seq.begin()) {
ans.emplace_back(*(i - 1), *i);
}
}
unordered_set<int> comp;
for (auto &&v : seq) {
if (comp.count(scc[v])) {
ans.emplace_back(seq.back(), seq.front());
break;
}
comp.emplace(scc[v]);
}
}
cout << ans.size() << "\n";
for (auto &&[x, y] : ans) {
++x, ++y;
cout << x << " " << y << "\n";
}
}
} // namespace workspace