This documentation is automatically generated by competitive-verifier/competitive-verifier
// competitive-verifier: PROBLEM https://judge.yosupo.jp/problem/chromatic_number
#include <iostream>
#include "tools/chromatic_number.hpp"
using ll = long long;
int main() {
std::cin.tie(nullptr);
std::ios_base::sync_with_stdio(false);
ll N, M;
std::cin >> N >> M;
tools::chromatic_number graph(N);
for (ll i = 0; i < M; ++i) {
ll u, v;
std::cin >> u >> v;
graph.add_edge(u, v);
}
std::cout << graph.query() << '\n';
return 0;
}
#line 1 "tests/chromatic_number.test.cpp"
// competitive-verifier: PROBLEM https://judge.yosupo.jp/problem/chromatic_number
#include <iostream>
#line 1 "tools/chromatic_number.hpp"
#include <vector>
#include <cstddef>
#include <cassert>
#line 1 "lib/ac-library/atcoder/modint.hpp"
#line 5 "lib/ac-library/atcoder/modint.hpp"
#include <numeric>
#include <type_traits>
#ifdef _MSC_VER
#include <intrin.h>
#endif
#line 1 "lib/ac-library/atcoder/internal_math.hpp"
#include <utility>
#ifdef _MSC_VER
#include <intrin.h>
#endif
namespace atcoder {
namespace internal {
// @param m `1 <= m`
// @return x mod m
constexpr long long safe_mod(long long x, long long m) {
x %= m;
if (x < 0) x += m;
return x;
}
// Fast modular multiplication by barrett reduction
// Reference: https://en.wikipedia.org/wiki/Barrett_reduction
// NOTE: reconsider after Ice Lake
struct barrett {
unsigned int _m;
unsigned long long im;
// @param m `1 <= m`
explicit barrett(unsigned int m) : _m(m), im((unsigned long long)(-1) / m + 1) {}
// @return m
unsigned int umod() const { return _m; }
// @param a `0 <= a < m`
// @param b `0 <= b < m`
// @return `a * b % m`
unsigned int mul(unsigned int a, unsigned int b) const {
// [1] m = 1
// a = b = im = 0, so okay
// [2] m >= 2
// im = ceil(2^64 / m)
// -> im * m = 2^64 + r (0 <= r < m)
// let z = a*b = c*m + d (0 <= c, d < m)
// a*b * im = (c*m + d) * im = c*(im*m) + d*im = c*2^64 + c*r + d*im
// c*r + d*im < m * m + m * im < m * m + 2^64 + m <= 2^64 + m * (m + 1) < 2^64 * 2
// ((ab * im) >> 64) == c or c + 1
unsigned long long z = a;
z *= b;
#ifdef _MSC_VER
unsigned long long x;
_umul128(z, im, &x);
#else
unsigned long long x =
(unsigned long long)(((unsigned __int128)(z)*im) >> 64);
#endif
unsigned long long y = x * _m;
return (unsigned int)(z - y + (z < y ? _m : 0));
}
};
// @param n `0 <= n`
// @param m `1 <= m`
// @return `(x ** n) % m`
constexpr long long pow_mod_constexpr(long long x, long long n, int m) {
if (m == 1) return 0;
unsigned int _m = (unsigned int)(m);
unsigned long long r = 1;
unsigned long long y = safe_mod(x, m);
while (n) {
if (n & 1) r = (r * y) % _m;
y = (y * y) % _m;
n >>= 1;
}
return r;
}
// Reference:
// M. Forisek and J. Jancina,
// Fast Primality Testing for Integers That Fit into a Machine Word
// @param n `0 <= n`
constexpr bool is_prime_constexpr(int n) {
if (n <= 1) return false;
if (n == 2 || n == 7 || n == 61) return true;
if (n % 2 == 0) return false;
long long d = n - 1;
while (d % 2 == 0) d /= 2;
constexpr long long bases[3] = {2, 7, 61};
for (long long a : bases) {
long long t = d;
long long y = pow_mod_constexpr(a, t, n);
while (t != n - 1 && y != 1 && y != n - 1) {
y = y * y % n;
t <<= 1;
}
if (y != n - 1 && t % 2 == 0) {
return false;
}
}
return true;
}
template <int n> constexpr bool is_prime = is_prime_constexpr(n);
// @param b `1 <= b`
// @return pair(g, x) s.t. g = gcd(a, b), xa = g (mod b), 0 <= x < b/g
constexpr std::pair<long long, long long> inv_gcd(long long a, long long b) {
a = safe_mod(a, b);
if (a == 0) return {b, 0};
// Contracts:
// [1] s - m0 * a = 0 (mod b)
// [2] t - m1 * a = 0 (mod b)
// [3] s * |m1| + t * |m0| <= b
long long s = b, t = a;
long long m0 = 0, m1 = 1;
while (t) {
long long u = s / t;
s -= t * u;
m0 -= m1 * u; // |m1 * u| <= |m1| * s <= b
// [3]:
// (s - t * u) * |m1| + t * |m0 - m1 * u|
// <= s * |m1| - t * u * |m1| + t * (|m0| + |m1| * u)
// = s * |m1| + t * |m0| <= b
auto tmp = s;
s = t;
t = tmp;
tmp = m0;
m0 = m1;
m1 = tmp;
}
// by [3]: |m0| <= b/g
// by g != b: |m0| < b/g
if (m0 < 0) m0 += b / s;
return {s, m0};
}
// Compile time primitive root
// @param m must be prime
// @return primitive root (and minimum in now)
constexpr int primitive_root_constexpr(int m) {
if (m == 2) return 1;
if (m == 167772161) return 3;
if (m == 469762049) return 3;
if (m == 754974721) return 11;
if (m == 998244353) return 3;
int divs[20] = {};
divs[0] = 2;
int cnt = 1;
int x = (m - 1) / 2;
while (x % 2 == 0) x /= 2;
for (int i = 3; (long long)(i)*i <= x; i += 2) {
if (x % i == 0) {
divs[cnt++] = i;
while (x % i == 0) {
x /= i;
}
}
}
if (x > 1) {
divs[cnt++] = x;
}
for (int g = 2;; g++) {
bool ok = true;
for (int i = 0; i < cnt; i++) {
if (pow_mod_constexpr(g, (m - 1) / divs[i], m) == 1) {
ok = false;
break;
}
}
if (ok) return g;
}
}
template <int m> constexpr int primitive_root = primitive_root_constexpr(m);
// @param n `n < 2^32`
// @param m `1 <= m < 2^32`
// @return sum_{i=0}^{n-1} floor((ai + b) / m) (mod 2^64)
unsigned long long floor_sum_unsigned(unsigned long long n,
unsigned long long m,
unsigned long long a,
unsigned long long b) {
unsigned long long ans = 0;
while (true) {
if (a >= m) {
ans += n * (n - 1) / 2 * (a / m);
a %= m;
}
if (b >= m) {
ans += n * (b / m);
b %= m;
}
unsigned long long y_max = a * n + b;
if (y_max < m) break;
// y_max < m * (n + 1)
// floor(y_max / m) <= n
n = (unsigned long long)(y_max / m);
b = (unsigned long long)(y_max % m);
std::swap(m, a);
}
return ans;
}
} // namespace internal
} // namespace atcoder
#line 1 "lib/ac-library/atcoder/internal_type_traits.hpp"
#line 7 "lib/ac-library/atcoder/internal_type_traits.hpp"
namespace atcoder {
namespace internal {
#ifndef _MSC_VER
template <class T>
using is_signed_int128 =
typename std::conditional<std::is_same<T, __int128_t>::value ||
std::is_same<T, __int128>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int128 =
typename std::conditional<std::is_same<T, __uint128_t>::value ||
std::is_same<T, unsigned __int128>::value,
std::true_type,
std::false_type>::type;
template <class T>
using make_unsigned_int128 =
typename std::conditional<std::is_same<T, __int128_t>::value,
__uint128_t,
unsigned __int128>;
template <class T>
using is_integral = typename std::conditional<std::is_integral<T>::value ||
is_signed_int128<T>::value ||
is_unsigned_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_signed_int = typename std::conditional<(is_integral<T>::value &&
std::is_signed<T>::value) ||
is_signed_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int =
typename std::conditional<(is_integral<T>::value &&
std::is_unsigned<T>::value) ||
is_unsigned_int128<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using to_unsigned = typename std::conditional<
is_signed_int128<T>::value,
make_unsigned_int128<T>,
typename std::conditional<std::is_signed<T>::value,
std::make_unsigned<T>,
std::common_type<T>>::type>::type;
#else
template <class T> using is_integral = typename std::is_integral<T>;
template <class T>
using is_signed_int =
typename std::conditional<is_integral<T>::value && std::is_signed<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using is_unsigned_int =
typename std::conditional<is_integral<T>::value &&
std::is_unsigned<T>::value,
std::true_type,
std::false_type>::type;
template <class T>
using to_unsigned = typename std::conditional<is_signed_int<T>::value,
std::make_unsigned<T>,
std::common_type<T>>::type;
#endif
template <class T>
using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>;
template <class T>
using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>;
template <class T> using to_unsigned_t = typename to_unsigned<T>::type;
} // namespace internal
} // namespace atcoder
#line 14 "lib/ac-library/atcoder/modint.hpp"
namespace atcoder {
namespace internal {
struct modint_base {};
struct static_modint_base : modint_base {};
template <class T> using is_modint = std::is_base_of<modint_base, T>;
template <class T> using is_modint_t = std::enable_if_t<is_modint<T>::value>;
} // namespace internal
template <int m, std::enable_if_t<(1 <= m)>* = nullptr>
struct static_modint : internal::static_modint_base {
using mint = static_modint;
public:
static constexpr int mod() { return m; }
static mint raw(int v) {
mint x;
x._v = v;
return x;
}
static_modint() : _v(0) {}
template <class T, internal::is_signed_int_t<T>* = nullptr>
static_modint(T v) {
long long x = (long long)(v % (long long)(umod()));
if (x < 0) x += umod();
_v = (unsigned int)(x);
}
template <class T, internal::is_unsigned_int_t<T>* = nullptr>
static_modint(T v) {
_v = (unsigned int)(v % umod());
}
unsigned int val() const { return _v; }
mint& operator++() {
_v++;
if (_v == umod()) _v = 0;
return *this;
}
mint& operator--() {
if (_v == 0) _v = umod();
_v--;
return *this;
}
mint operator++(int) {
mint result = *this;
++*this;
return result;
}
mint operator--(int) {
mint result = *this;
--*this;
return result;
}
mint& operator+=(const mint& rhs) {
_v += rhs._v;
if (_v >= umod()) _v -= umod();
return *this;
}
mint& operator-=(const mint& rhs) {
_v -= rhs._v;
if (_v >= umod()) _v += umod();
return *this;
}
mint& operator*=(const mint& rhs) {
unsigned long long z = _v;
z *= rhs._v;
_v = (unsigned int)(z % umod());
return *this;
}
mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); }
mint operator+() const { return *this; }
mint operator-() const { return mint() - *this; }
mint pow(long long n) const {
assert(0 <= n);
mint x = *this, r = 1;
while (n) {
if (n & 1) r *= x;
x *= x;
n >>= 1;
}
return r;
}
mint inv() const {
if (prime) {
assert(_v);
return pow(umod() - 2);
} else {
auto eg = internal::inv_gcd(_v, m);
assert(eg.first == 1);
return eg.second;
}
}
friend mint operator+(const mint& lhs, const mint& rhs) {
return mint(lhs) += rhs;
}
friend mint operator-(const mint& lhs, const mint& rhs) {
return mint(lhs) -= rhs;
}
friend mint operator*(const mint& lhs, const mint& rhs) {
return mint(lhs) *= rhs;
}
friend mint operator/(const mint& lhs, const mint& rhs) {
return mint(lhs) /= rhs;
}
friend bool operator==(const mint& lhs, const mint& rhs) {
return lhs._v == rhs._v;
}
friend bool operator!=(const mint& lhs, const mint& rhs) {
return lhs._v != rhs._v;
}
private:
unsigned int _v;
static constexpr unsigned int umod() { return m; }
static constexpr bool prime = internal::is_prime<m>;
};
template <int id> struct dynamic_modint : internal::modint_base {
using mint = dynamic_modint;
public:
static int mod() { return (int)(bt.umod()); }
static void set_mod(int m) {
assert(1 <= m);
bt = internal::barrett(m);
}
static mint raw(int v) {
mint x;
x._v = v;
return x;
}
dynamic_modint() : _v(0) {}
template <class T, internal::is_signed_int_t<T>* = nullptr>
dynamic_modint(T v) {
long long x = (long long)(v % (long long)(mod()));
if (x < 0) x += mod();
_v = (unsigned int)(x);
}
template <class T, internal::is_unsigned_int_t<T>* = nullptr>
dynamic_modint(T v) {
_v = (unsigned int)(v % mod());
}
unsigned int val() const { return _v; }
mint& operator++() {
_v++;
if (_v == umod()) _v = 0;
return *this;
}
mint& operator--() {
if (_v == 0) _v = umod();
_v--;
return *this;
}
mint operator++(int) {
mint result = *this;
++*this;
return result;
}
mint operator--(int) {
mint result = *this;
--*this;
return result;
}
mint& operator+=(const mint& rhs) {
_v += rhs._v;
if (_v >= umod()) _v -= umod();
return *this;
}
mint& operator-=(const mint& rhs) {
_v += mod() - rhs._v;
if (_v >= umod()) _v -= umod();
return *this;
}
mint& operator*=(const mint& rhs) {
_v = bt.mul(_v, rhs._v);
return *this;
}
mint& operator/=(const mint& rhs) { return *this = *this * rhs.inv(); }
mint operator+() const { return *this; }
mint operator-() const { return mint() - *this; }
mint pow(long long n) const {
assert(0 <= n);
mint x = *this, r = 1;
while (n) {
if (n & 1) r *= x;
x *= x;
n >>= 1;
}
return r;
}
mint inv() const {
auto eg = internal::inv_gcd(_v, mod());
assert(eg.first == 1);
return eg.second;
}
friend mint operator+(const mint& lhs, const mint& rhs) {
return mint(lhs) += rhs;
}
friend mint operator-(const mint& lhs, const mint& rhs) {
return mint(lhs) -= rhs;
}
friend mint operator*(const mint& lhs, const mint& rhs) {
return mint(lhs) *= rhs;
}
friend mint operator/(const mint& lhs, const mint& rhs) {
return mint(lhs) /= rhs;
}
friend bool operator==(const mint& lhs, const mint& rhs) {
return lhs._v == rhs._v;
}
friend bool operator!=(const mint& lhs, const mint& rhs) {
return lhs._v != rhs._v;
}
private:
unsigned int _v;
static internal::barrett bt;
static unsigned int umod() { return bt.umod(); }
};
template <int id> internal::barrett dynamic_modint<id>::bt(998244353);
using modint998244353 = static_modint<998244353>;
using modint1000000007 = static_modint<1000000007>;
using modint = dynamic_modint<-1>;
namespace internal {
template <class T>
using is_static_modint = std::is_base_of<internal::static_modint_base, T>;
template <class T>
using is_static_modint_t = std::enable_if_t<is_static_modint<T>::value>;
template <class> struct is_dynamic_modint : public std::false_type {};
template <int id>
struct is_dynamic_modint<dynamic_modint<id>> : public std::true_type {};
template <class T>
using is_dynamic_modint_t = std::enable_if_t<is_dynamic_modint<T>::value>;
} // namespace internal
} // namespace atcoder
#line 1 "tools/countr_zero.hpp"
#include <algorithm>
#include <bit>
#line 7 "tools/countr_zero.hpp"
#include <limits>
#line 1 "tools/is_integral.hpp"
#line 5 "tools/is_integral.hpp"
namespace tools {
template <typename T>
struct is_integral : ::std::is_integral<T> {};
template <typename T>
inline constexpr bool is_integral_v = ::tools::is_integral<T>::value;
}
#line 1 "tools/is_signed.hpp"
#line 5 "tools/is_signed.hpp"
namespace tools {
template <typename T>
struct is_signed : ::std::is_signed<T> {};
template <typename T>
inline constexpr bool is_signed_v = ::tools::is_signed<T>::value;
}
#line 1 "tools/make_unsigned.hpp"
#line 5 "tools/make_unsigned.hpp"
namespace tools {
template <typename T>
struct make_unsigned : ::std::make_unsigned<T> {};
template <typename T>
using make_unsigned_t = typename ::tools::make_unsigned<T>::type;
}
#line 12 "tools/countr_zero.hpp"
namespace tools {
template <typename T>
constexpr int countr_zero(const T x) noexcept {
static_assert(::tools::is_integral_v<T> && !::std::is_same_v<::std::remove_cv_t<T>, bool>);
if constexpr (::tools::is_signed_v<T>) {
assert(x >= 0);
return ::std::min(::tools::countr_zero<::tools::make_unsigned_t<T>>(x), ::std::numeric_limits<T>::digits);
} else {
return ::std::countr_zero(x);
}
}
}
#line 1 "tools/popcount.hpp"
#line 1 "tools/uint128_t.hpp"
#line 1 "tools/detail/int128_t.hpp"
#line 7 "tools/detail/int128_t.hpp"
#include <cstdint>
#include <functional>
#line 11 "tools/detail/int128_t.hpp"
#include <string>
#include <string_view>
#line 1 "tools/abs.hpp"
namespace tools {
constexpr float abs(const float x) {
return x < 0 ? -x : x;
}
constexpr double abs(const double x) {
return x < 0 ? -x : x;
}
constexpr long double abs(const long double x) {
return x < 0 ? -x : x;
}
constexpr int abs(const int x) {
return x < 0 ? -x : x;
}
constexpr long abs(const long x) {
return x < 0 ? -x : x;
}
constexpr long long abs(const long long x) {
return x < 0 ? -x : x;
}
constexpr unsigned int abs(const unsigned int x) {
return x;
}
constexpr unsigned long abs(const unsigned long x) {
return x;
}
constexpr unsigned long long abs(const unsigned long long x) {
return x;
}
}
#line 1 "tools/bit_ceil.hpp"
#line 10 "tools/bit_ceil.hpp"
namespace tools {
template <typename T>
constexpr T bit_ceil(T) noexcept;
template <typename T>
constexpr T bit_ceil(const T x) noexcept {
static_assert(::tools::is_integral_v<T> && !::std::is_same_v<::std::remove_cv_t<T>, bool>);
if constexpr (::tools::is_signed_v<T>) {
assert(x >= 0);
return ::tools::bit_ceil<::tools::make_unsigned_t<T>>(x);
} else {
return ::std::bit_ceil(x);
}
}
}
#line 1 "tools/bit_floor.hpp"
#line 10 "tools/bit_floor.hpp"
namespace tools {
template <typename T>
constexpr T bit_floor(T) noexcept;
template <typename T>
constexpr T bit_floor(const T x) noexcept {
static_assert(::tools::is_integral_v<T> && !::std::is_same_v<::std::remove_cv_t<T>, bool>);
if constexpr (::tools::is_signed_v<T>) {
assert(x >= 0);
return ::tools::bit_floor<::tools::make_unsigned_t<T>>(x);
} else {
return ::std::bit_floor(x);
}
}
}
#line 1 "tools/bit_width.hpp"
#line 10 "tools/bit_width.hpp"
namespace tools {
template <typename T>
constexpr int bit_width(T) noexcept;
template <typename T>
constexpr int bit_width(const T x) noexcept {
static_assert(::tools::is_integral_v<T> && !::std::is_same_v<::std::remove_cv_t<T>, bool>);
if constexpr (::tools::is_signed_v<T>) {
assert(x >= 0);
return ::tools::bit_width<::tools::make_unsigned_t<T>>(x);
} else {
return ::std::bit_width(x);
}
}
}
#line 1 "tools/is_unsigned.hpp"
#line 5 "tools/is_unsigned.hpp"
namespace tools {
template <typename T>
struct is_unsigned : ::std::is_unsigned<T> {};
template <typename T>
inline constexpr bool is_unsigned_v = ::tools::is_unsigned<T>::value;
}
#line 1 "tools/hash_combine.hpp"
#line 6 "tools/hash_combine.hpp"
// Source: https://github.com/google/cityhash/blob/f5dc54147fcce12cefd16548c8e760d68ac04226/src/city.h
// License: MIT
// Author: Google Inc.
// Copyright (c) 2011 Google, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
namespace tools {
template <typename T>
void hash_combine(::std::size_t& seed, const T& v) {
static const ::std::hash<T> hasher;
static constexpr ::std::size_t k_mul = 0x9ddfea08eb382d69ULL;
::std::size_t a = (hasher(v) ^ seed) * k_mul;
a ^= (a >> 47);
::std::size_t b = (seed ^ a) * k_mul;
b ^= (b >> 47);
seed = b * k_mul;
}
}
#line 1 "tools/make_signed.hpp"
#line 5 "tools/make_signed.hpp"
namespace tools {
template <typename T>
struct make_signed : ::std::make_signed<T> {};
template <typename T>
using make_signed_t = typename ::tools::make_signed<T>::type;
}
#line 1 "tools/now.hpp"
#include <chrono>
namespace tools {
inline long long now() {
return ::std::chrono::duration_cast<::std::chrono::nanoseconds>(::std::chrono::high_resolution_clock::now().time_since_epoch()).count();
}
}
#line 25 "tools/detail/int128_t.hpp"
namespace tools {
using uint128_t = unsigned __int128;
using int128_t = __int128;
namespace detail {
namespace int128_t {
constexpr ::tools::uint128_t parse_unsigned(const ::std::string_view s) noexcept {
assert(!s.empty());
::tools::uint128_t x = 0;
::std::size_t i = s[0] == '+';
if (i + 1 < s.size() && s[i] == '0' && (s[i + 1] == 'x' || s[i + 1] == 'X')) {
for (i += 2; i < s.size(); ++i) {
assert(('0' <= s[i] && s[i] <= '9') || ('a' <= s[i] && s[i] <= 'f') || ('A' <= s[i] && s[i] <= 'F'));
x <<= 4;
if ('0' <= s[i] && s[i] <= '9') {
x |= s[i] - '0';
} else if ('a' <= s[i] && s[i] <= 'f') {
x |= s[i] - 'a' + 10;
} else {
x |= s[i] - 'A' + 10;
}
}
} else {
for (; i < s.size(); ++i) {
assert('0' <= s[i] && s[i] <= '9');
x *= 10;
x += s[i] - '0';
}
}
return x;
}
constexpr ::tools::int128_t parse_signed(const ::std::string_view s) noexcept {
assert(!s.empty());
::tools::int128_t x = 0;
if (s[0] == '-') {
::std::size_t i = 1;
if (i + 1 < s.size() && s[i] == '0' && (s[i + 1] == 'x' || s[i + 1] == 'X')) {
for (i += 2; i < s.size(); ++i) {
assert(('0' <= s[i] && s[i] <= '9') || ('a' <= s[i] && s[i] <= 'f') || ('A' <= s[i] && s[i] <= 'F'));
x *= 16;
if ('0' <= s[i] && s[i] <= '9') {
x -= s[i] - '0';
} else if ('a' <= s[i] && s[i] <= 'f') {
x -= s[i] - 'a' + 10;
} else {
x -= s[i] - 'A' + 10;
}
}
} else {
for (; i < s.size(); ++i) {
assert('0' <= s[i] && s[i] <= '9');
x *= 10;
x -= s[i] - '0';
}
}
} else {
::std::size_t i = s[0] == '+';
if (i + 1 < s.size() && s[i] == '0' && (s[i + 1] == 'x' || s[i + 1] == 'X')) {
for (i += 2; i < s.size(); ++i) {
assert(('0' <= s[i] && s[i] <= '9') || ('a' <= s[i] && s[i] <= 'f') || ('A' <= s[i] && s[i] <= 'F'));
x <<= 4;
if ('0' <= s[i] && s[i] <= '9') {
x |= s[i] - '0';
} else if ('a' <= s[i] && s[i] <= 'f') {
x |= s[i] - 'a' + 10;
} else {
x |= s[i] - 'A' + 10;
}
}
} else {
for (; i < s.size(); ++i) {
assert('0' <= s[i] && s[i] <= '9');
x *= 10;
x += s[i] - '0';
}
}
}
return x;
}
}
}
constexpr ::tools::uint128_t abs(const ::tools::uint128_t& x) noexcept {
return x;
}
constexpr ::tools::int128_t abs(const ::tools::int128_t& x) {
return x >= 0 ? x : -x;
}
}
#define UINT128_C(c) ::tools::detail::int128_t::parse_unsigned(#c)
#define INT128_C(c) ::tools::detail::int128_t::parse_signed(#c)
inline ::std::istream& operator>>(::std::istream& is, ::tools::uint128_t& x) {
::std::string s;
is >> s;
x = ::tools::detail::int128_t::parse_unsigned(s);
return is;
}
inline ::std::istream& operator>>(::std::istream& is, ::tools::int128_t& x) {
::std::string s;
is >> s;
x = ::tools::detail::int128_t::parse_signed(s);
return is;
}
inline ::std::ostream& operator<<(::std::ostream& os, ::tools::uint128_t x) {
::std::string s;
if (x > 0) {
while (x > 0) {
s.push_back('0' + x % 10);
x /= 10;
}
} else {
s.push_back('0');
}
::std::ranges::reverse(s);
return os << s;
}
inline ::std::ostream& operator<<(::std::ostream& os, ::tools::int128_t x) {
::std::string s;
if (x > 0) {
while (x > 0) {
s.push_back('0' + x % 10);
x /= 10;
}
} else if (x < 0) {
while (x < 0) {
s.push_back('0' + (-(x % 10)));
x /= 10;
}
s.push_back('-');
} else {
s.push_back('0');
}
::std::ranges::reverse(s);
return os << s;
}
#if defined(__GLIBCXX__) && defined(__STRICT_ANSI__)
namespace std {
template <>
struct hash<::tools::uint128_t> {
::std::size_t operator()(const ::tools::uint128_t& x) const {
static const ::std::size_t seed = ::tools::now();
::std::size_t hash = seed;
::tools::hash_combine(hash, static_cast<::std::uint64_t>(x >> 64));
::tools::hash_combine(hash, static_cast<::std::uint64_t>(x & ((UINT128_C(1) << 64) - 1)));
return hash;
}
};
template <>
struct hash<::tools::int128_t> {
::std::size_t operator()(const ::tools::int128_t& x) const {
static ::std::hash<::tools::uint128_t> hasher;
return hasher(static_cast<::tools::uint128_t>(x));
}
};
}
#endif
namespace tools {
template <>
struct is_integral<::tools::int128_t> : ::std::true_type {};
template <>
struct is_integral<::tools::uint128_t> : ::std::true_type {};
template <>
struct is_integral<const ::tools::int128_t> : ::std::true_type {};
template <>
struct is_integral<const ::tools::uint128_t> : ::std::true_type {};
template <>
struct is_integral<volatile ::tools::int128_t> : ::std::true_type {};
template <>
struct is_integral<volatile ::tools::uint128_t> : ::std::true_type {};
template <>
struct is_integral<const volatile ::tools::int128_t> : ::std::true_type {};
template <>
struct is_integral<const volatile ::tools::uint128_t> : ::std::true_type {};
template <>
struct is_signed<::tools::int128_t> : ::std::true_type {};
template <>
struct is_signed<::tools::uint128_t> : ::std::false_type {};
template <>
struct is_signed<const ::tools::int128_t> : ::std::true_type {};
template <>
struct is_signed<const ::tools::uint128_t> : ::std::false_type {};
template <>
struct is_signed<volatile ::tools::int128_t> : ::std::true_type {};
template <>
struct is_signed<volatile ::tools::uint128_t> : ::std::false_type {};
template <>
struct is_signed<const volatile ::tools::int128_t> : ::std::true_type {};
template <>
struct is_signed<const volatile ::tools::uint128_t> : ::std::false_type {};
template <>
struct is_unsigned<::tools::int128_t> : ::std::false_type {};
template <>
struct is_unsigned<::tools::uint128_t> : ::std::true_type {};
template <>
struct is_unsigned<const ::tools::int128_t> : ::std::false_type {};
template <>
struct is_unsigned<const ::tools::uint128_t> : ::std::true_type {};
template <>
struct is_unsigned<volatile ::tools::int128_t> : ::std::false_type {};
template <>
struct is_unsigned<volatile ::tools::uint128_t> : ::std::true_type {};
template <>
struct is_unsigned<const volatile ::tools::int128_t> : ::std::false_type {};
template <>
struct is_unsigned<const volatile ::tools::uint128_t> : ::std::true_type {};
template <>
struct make_signed<::tools::int128_t> {
using type = ::tools::int128_t;
};
template <>
struct make_signed<::tools::uint128_t> {
using type = ::tools::int128_t;
};
template <>
struct make_signed<const ::tools::int128_t> {
using type = const ::tools::int128_t;
};
template <>
struct make_signed<const ::tools::uint128_t> {
using type = const ::tools::int128_t;
};
template <>
struct make_signed<volatile ::tools::int128_t> {
using type = volatile ::tools::int128_t;
};
template <>
struct make_signed<volatile ::tools::uint128_t> {
using type = volatile ::tools::int128_t;
};
template <>
struct make_signed<const volatile ::tools::int128_t> {
using type = const volatile ::tools::int128_t;
};
template <>
struct make_signed<const volatile ::tools::uint128_t> {
using type = const volatile ::tools::int128_t;
};
template <>
struct make_unsigned<::tools::int128_t> {
using type = ::tools::uint128_t;
};
template <>
struct make_unsigned<::tools::uint128_t> {
using type = ::tools::uint128_t;
};
template <>
struct make_unsigned<const ::tools::int128_t> {
using type = const ::tools::uint128_t;
};
template <>
struct make_unsigned<const ::tools::uint128_t> {
using type = const ::tools::uint128_t;
};
template <>
struct make_unsigned<volatile ::tools::int128_t> {
using type = volatile ::tools::uint128_t;
};
template <>
struct make_unsigned<volatile ::tools::uint128_t> {
using type = volatile ::tools::uint128_t;
};
template <>
struct make_unsigned<const volatile ::tools::int128_t> {
using type = const volatile ::tools::uint128_t;
};
template <>
struct make_unsigned<const volatile ::tools::uint128_t> {
using type = const volatile ::tools::uint128_t;
};
#if defined(__GLIBCXX__) && defined(__STRICT_ANSI__)
template <>
constexpr ::tools::uint128_t bit_ceil<::tools::uint128_t>(::tools::uint128_t x) noexcept {
if (x <= 1) return 1;
--x;
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
x |= x >> 32;
x |= x >> 64;
return ++x;
}
template <>
constexpr ::tools::uint128_t bit_floor<::tools::uint128_t>(::tools::uint128_t x) noexcept {
x |= x >> 1;
x |= x >> 2;
x |= x >> 4;
x |= x >> 8;
x |= x >> 16;
x |= x >> 32;
x |= x >> 64;
return x & ~(x >> 1);
}
template <>
constexpr int bit_width<::tools::uint128_t>(::tools::uint128_t x) noexcept {
int w = 0;
if (x & UINT128_C(0xffffffffffffffff0000000000000000)) {
x >>= 64;
w += 64;
}
if (x & UINT128_C(0xffffffff00000000)) {
x >>= 32;
w += 32;
}
if (x & UINT128_C(0xffff0000)) {
x >>= 16;
w += 16;
}
if (x & UINT128_C(0xff00)) {
x >>= 8;
w += 8;
}
if (x & UINT128_C(0xf0)) {
x >>= 4;
w += 4;
}
if (x & UINT128_C(0xc)) {
x >>= 2;
w += 2;
}
if (x & UINT128_C(0x2)) {
x >>= 1;
w += 1;
}
w += x;
return w;
}
namespace detail {
namespace countr_zero {
template <::std::size_t N>
struct ntz_traits;
template <>
struct ntz_traits<128> {
using type = ::tools::uint128_t;
static constexpr int shift = 120;
static constexpr type magic = UINT128_C(0x01061438916347932a5cd9d3ead7b77f);
static constexpr int ntz_table[255] = {
128, 0, 1, -1, 2, -1, 8, -1, 3, -1, 15, -1, 9, -1, 22, -1,
4, -1, 29, -1, 16, -1, 36, -1, 10, -1, 43, -1, 23, -1, 50, -1,
5, -1, 33, -1, 30, -1, 57, -1, 17, -1, 64, -1, 37, -1, 71, -1,
11, -1, 60, -1, 44, -1, 78, -1, 24, -1, 85, -1, 51, -1, 92, -1,
-1, 6, -1, 20, -1, 34, -1, 48, 31, -1, -1, 69, 58, -1, -1, 90,
18, -1, 67, -1, 65, -1, 99, -1, 38, -1, 101, -1, 72, -1, 106, -1,
-1, 12, -1, 40, -1, 61, -1, 82, 45, -1, -1, 103, 79, -1, 113, -1,
-1, 25, -1, 74, 86, -1, -1, 116, -1, 52, -1, 108, -1, 93, -1, 120,
127, -1, -1, 7, -1, 14, -1, 21, -1, 28, -1, 35, -1, 42, -1, 49,
-1, 32, -1, 56, -1, 63, -1, 70, -1, 59, -1, 77, -1, 84, -1, 91,
-1, 19, -1, 47, -1, 68, -1, 89, -1, 66, -1, 98, -1, 100, -1, 105,
-1, 39, -1, 81, -1, 102, -1, 112, -1, 73, -1, 115, -1, 107, -1, 119,
126, -1, 13, -1, 27, -1, 41, -1, -1, 55, 62, -1, -1, 76, 83, -1,
-1, 46, -1, 88, -1, 97, -1, 104, -1, 80, -1, 111, -1, 114, -1, 118,
125, -1, 26, -1, 54, -1, 75, -1, -1, 87, 96, -1, -1, 110, -1, 117,
124, -1, 53, -1, -1, 95, 109, -1, 123, -1, 94, -1, 122, -1, 121
};
};
template <typename T>
constexpr int impl(const T x) noexcept {
using tr = ::tools::detail::countr_zero::ntz_traits<::std::numeric_limits<T>::digits>;
using type = typename tr::type;
return tr::ntz_table[static_cast<type>(tr::magic * static_cast<type>(x & -x)) >> tr::shift];
}
}
}
template <>
constexpr int countr_zero<::tools::uint128_t>(const ::tools::uint128_t x) noexcept {
return ::tools::detail::countr_zero::impl(x);
}
#endif
}
#line 5 "tools/uint128_t.hpp"
#line 11 "tools/popcount.hpp"
namespace tools {
template <typename T>
constexpr int popcount(T) noexcept;
template <typename T>
constexpr int popcount(const T x) noexcept {
static_assert(::tools::is_integral_v<T> && !::std::is_same_v<::std::remove_cv_t<T>, bool>);
if constexpr (::tools::is_signed_v<T>) {
assert(x >= 0);
return ::tools::popcount<::tools::make_unsigned_t<T>>(x);
} else {
return ::std::popcount(x);
}
}
#if defined(__GLIBCXX__) && defined(__STRICT_ANSI__)
template <>
constexpr int popcount<::tools::uint128_t>(::tools::uint128_t x) noexcept {
x = (x & UINT128_C(0x55555555555555555555555555555555)) + (x >> 1 & UINT128_C(0x55555555555555555555555555555555));
x = (x & UINT128_C(0x33333333333333333333333333333333)) + (x >> 2 & UINT128_C(0x33333333333333333333333333333333));
x = (x & UINT128_C(0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f)) + (x >> 4 & UINT128_C(0x0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f0f));
x = (x & UINT128_C(0x00ff00ff00ff00ff00ff00ff00ff00ff)) + (x >> 8 & UINT128_C(0x00ff00ff00ff00ff00ff00ff00ff00ff));
x = (x & UINT128_C(0x0000ffff0000ffff0000ffff0000ffff)) + (x >> 16 & UINT128_C(0x0000ffff0000ffff0000ffff0000ffff));
x = (x & UINT128_C(0x00000000ffffffff00000000ffffffff)) + (x >> 32 & UINT128_C(0x00000000ffffffff00000000ffffffff));
x = (x & UINT128_C(0x0000000000000000ffffffffffffffff)) + (x >> 64 & UINT128_C(0x0000000000000000ffffffffffffffff));
return x;
}
#endif
}
#line 10 "tools/chromatic_number.hpp"
// Source: https://drken1215.hatenablog.com/entry/2019/01/16/030000
// License: unknown
// Author: drken
namespace tools {
class chromatic_number {
private:
::std::vector<unsigned long long> neighbor;
public:
chromatic_number() = default;
chromatic_number(const ::tools::chromatic_number&) = default;
chromatic_number(::tools::chromatic_number&&) = default;
~chromatic_number() = default;
::tools::chromatic_number& operator=(const ::tools::chromatic_number&) = default;
::tools::chromatic_number& operator=(::tools::chromatic_number&&) = default;
explicit chromatic_number(const ::std::size_t n) : neighbor(n) {
for (::std::size_t i = 0; i < n; ++i) {
this->neighbor[i] = (1ULL << i);
}
}
::std::size_t node_count() const {
return this->neighbor.size();
}
void add_edge(const ::std::size_t s, const ::std::size_t t) {
assert(s < this->node_count());
assert(t < this->node_count());
this->neighbor[s] |= (1ULL << t);
this->neighbor[t] |= (1ULL << s);
}
long long query() const {
const auto pow2 = [](const unsigned long long x) {
return 1ULL << x;
};
const auto& set = pow2;
// I[S] := #. of indepndent subsets of S
::std::vector<::atcoder::modint1000000007> I(pow2(this->node_count()));
I[0] = ::atcoder::modint1000000007(1);
for (unsigned long long S = 1; S < pow2(this->node_count()); ++S) {
const unsigned long long v = ::tools::countr_zero(S);
I[S] = I[S & ~set(v)] + I[S & ~this->neighbor[v]];
}
long long ng = 0;
long long ok = this->node_count();
while (ok - ng > 1) {
long long k = (ok + ng) / 2;
// g[S] := #. of "k independent sets" which cover S just
// f[S] := #. of "k independent sets" which consist of subsets of S
// then
// f[S] = sum_{T in S} g(T)
// g[S] = sum_{T in S} (-1)^(|S|-|T|)f[T]
::atcoder::modint1000000007 g(0);
for (unsigned long long S = 0; S < pow2(this->node_count()); ++S) {
if ((static_cast<unsigned long long>(this->node_count()) - ::tools::popcount(S)) & 1) {
g -= I[S].pow(k);
} else {
g += I[S].pow(k);
}
}
if (g.val() != 0) {
ok = k;
} else {
ng = k;
}
}
return ok;
}
};
}
#line 5 "tests/chromatic_number.test.cpp"
using ll = long long;
int main() {
std::cin.tie(nullptr);
std::ios_base::sync_with_stdio(false);
ll N, M;
std::cin >> N >> M;
tools::chromatic_number graph(N);
for (ll i = 0; i < M; ++i) {
ll u, v;
std::cin >> u >> v;
graph.add_edge(u, v);
}
std::cout << graph.query() << '\n';
return 0;
}
Env | Name | Status | Elapsed | Memory |
---|---|---|---|---|
g++ | big_00 |
![]() |
9 ms | 4 MB |
g++ | big_01 |
![]() |
13 ms | 4 MB |
g++ | big_02 |
![]() |
48 ms | 7 MB |
g++ | big_03 |
![]() |
10 ms | 4 MB |
g++ | big_04 |
![]() |
50 ms | 7 MB |
g++ | big_05 |
![]() |
15 ms | 4 MB |
g++ | big_06 |
![]() |
15 ms | 4 MB |
g++ | big_07 |
![]() |
29 ms | 5 MB |
g++ | big_08 |
![]() |
50 ms | 7 MB |
g++ | big_09 |
![]() |
9 ms | 4 MB |
g++ | clique_cycle_00 |
![]() |
59 ms | 7 MB |
g++ | clique_cycle_01 |
![]() |
59 ms | 7 MB |
g++ | clique_cycle_02 |
![]() |
48 ms | 7 MB |
g++ | clique_cycle_03 |
![]() |
72 ms | 7 MB |
g++ | example_00 |
![]() |
4 ms | 4 MB |
g++ | example_01 |
![]() |
39 ms | 7 MB |
g++ | random_00 |
![]() |
4 ms | 4 MB |
g++ | random_01 |
![]() |
4 ms | 4 MB |
g++ | random_02 |
![]() |
4 ms | 3 MB |
g++ | random_03 |
![]() |
4 ms | 3 MB |
g++ | random_04 |
![]() |
50 ms | 7 MB |
g++ | random_05 |
![]() |
4 ms | 4 MB |
g++ | random_06 |
![]() |
4 ms | 4 MB |
g++ | random_07 |
![]() |
29 ms | 5 MB |
g++ | random_08 |
![]() |
5 ms | 4 MB |
g++ | random_09 |
![]() |
4 ms | 3 MB |