Submission #742291

#	Time	Username	Problem	Language	Result	Execution time	Memory
742291		josanneo22	Rack (eJOI19_rack)	C++17	40 / 100	1 ms	212 KiB

rack

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

#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define fi first
#define se second 
template <typename T>
T inverse(T a, T m) {
	T u = 0, v = 1;
	while (a != 0) {
		T t = m / a;
		m -= t * a; swap(a, m);
		u -= t * v; swap(u, v);
	}
	assert(m == 1);
	return u;
}

template <typename T>
class Modular {
public:
	using Type = typename decay<decltype(T::value)>::type;

	constexpr Modular() : value() {}
	template <typename U>
	Modular(const U& x) {
		value = normalize(x);
	}

	template <typename U>
	static Type normalize(const U& x) {
		Type v;
		if (-mod() <= x && x < mod()) v = static_cast<Type>(x);
		else v = static_cast<Type>(x % mod());
		if (v < 0) v += mod();
		return v;
	}

	const Type& operator()() const { return value; }
	template <typename U>
	explicit operator U() const { return static_cast<U>(value); }
	constexpr static Type mod() { return T::value; }

	Modular& operator+=(const Modular& other) { if ((value += other.value) >= mod()) value -= mod(); return (*this); }
	Modular& operator-=(const Modular& other) { if ((value -= other.value) < 0) value += mod(); return (*this); }
	template <typename U> Modular& operator+=(const U& other) { return (*this) += Modular(other); }
	template <typename U> Modular& operator-=(const U& other) { return (*this) -= Modular(other); }
	Modular& operator++() { return (*this) += 1; }
	Modular& operator--() { return (*this) -= 1; }
	Modular operator++(int) { Modular result(*this); (*this) += 1; return result; }
	Modular operator--(int) { Modular result(*this); (*this) -= 1; return result; }
	Modular operator-() const { return Modular(-value); }

	template <typename U = T>
	typename enable_if<is_same<typename Modular<U>::Type, int>::value, Modular>::type& operator*=(const Modular& rhs) {
		value = normalize(static_cast<int64_t>(value) * static_cast<int64_t>(rhs.value));
		return (*this);
	}
	template <typename U = T>
	typename enable_if<is_same<typename Modular<U>::Type, int64_t>::value, Modular>::type& operator*=(const Modular& rhs) {
		int64_t q = static_cast<int64_t>(static_cast<long double>(value) * rhs.value / mod());
		value = normalize(value * rhs.value - q * mod());
		return (*this);
	}
	template <typename U = T>
	typename enable_if<!is_integral<typename Modular<U>::Type>::value, Modular>::type& operator*=(const Modular& rhs) {
		value = normalize(value * rhs.value);
		return (*this);
	}

	Modular& operator/=(const Modular& other) { return (*this) *= Modular(inverse(other.value, mod())); }

	template <typename U>
	friend const Modular<U>& abs(const Modular<U>& v) { return v; }

	template <typename U>
	friend bool operator==(const Modular<U>& lhs, const Modular<U>& rhs);

	template <typename U>
	friend bool operator<(const Modular<U>& lhs, const Modular<U>& rhs);

	template <typename U>
	friend std::istream& operator>>(std::istream& stream, Modular<U>& number);

private:
	Type value;
};

template <typename T> bool operator==(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value == rhs.value; }
template <typename T, typename U> bool operator==(const Modular<T>& lhs, U rhs) { return lhs == Modular<T>(rhs); }
template <typename T, typename U> bool operator==(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) == rhs; }

template <typename T> bool operator!=(const Modular<T>& lhs, const Modular<T>& rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(const Modular<T>& lhs, U rhs) { return !(lhs == rhs); }
template <typename T, typename U> bool operator!=(U lhs, const Modular<T>& rhs) { return !(lhs == rhs); }

template <typename T> bool operator<(const Modular<T>& lhs, const Modular<T>& rhs) { return lhs.value < rhs.value; }

template <typename T> Modular<T> operator+(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) += rhs; }
template <typename T, typename U> Modular<T> operator+(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) += rhs; }

template <typename T> Modular<T> operator-(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) -= rhs; }
template <typename T, typename U> Modular<T> operator-(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) -= rhs; }

template <typename T> Modular<T> operator*(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) *= rhs; }
template <typename T, typename U> Modular<T> operator*(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) *= rhs; }

template <typename T> Modular<T> operator/(const Modular<T>& lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(const Modular<T>& lhs, U rhs) { return Modular<T>(lhs) /= rhs; }
template <typename T, typename U> Modular<T> operator/(U lhs, const Modular<T>& rhs) { return Modular<T>(lhs) /= rhs; }

template<typename T, typename U>
Modular<T> power(const Modular<T>& a, const U& b) {
	assert(b >= 0);
	Modular<T> x = a, res = 1;
	U p = b;
	while (p > 0) {
		if (p & 1) res *= x;
		x *= x;
		p >>= 1;
	}
	return res;
}

template <typename T>
bool IsZero(const Modular<T>& number) {
	return number() == 0;
}

template <typename T>
string to_string(const Modular<T>& number) {
	return to_string(number());
}

template <typename T>
std::ostream& operator<<(std::ostream& stream, const Modular<T>& number) {
	return stream << number();
}

template <typename T>
std::istream& operator>>(std::istream& stream, Modular<T>& number) {
	typename common_type<typename Modular<T>::Type, int64_t>::type x;
	stream >> x;
	number.value = Modular<T>::normalize(x);
	return stream;
}

/*
using ModType = int;

struct VarMod { static ModType value; };
ModType VarMod::value;
ModType& md = VarMod::value;
using Mint = Modular<VarMod>;
*/

constexpr int md = 998244353;
using Mint = Modular<std::integral_constant<decay<decltype(md)>::type, md>>;

vector<Mint> fact(1, 1);
vector<Mint> inv_fact(1, 1);

Mint C(int n, int k) {
	if (k < 0 || k > n) {
		return 0;
	}
	while ((int)fact.size() < n + 1) {
		fact.push_back(fact.back() * (int)fact.size());
		inv_fact.push_back(1 / fact.back());
	}
	return fact[n] * inv_fact[k] * inv_fact[n - k];
}

#define ll long long
vector<Mint> pw;
Mint get(ll u, ll v) {
	Mint res = 1;
	while (v) { 
		res += (v%2LL)*pw[u--];
		v /= 2;
	}
	return res;
}
void solve() {
	ll n, k; cin >> n >> k;
	pw.resize(n + 2);
	pw[0] = 1;
	for (int i = 1; i <= n; i++) {
		pw[i]=2*pw[i-1];
	}
	Mint ans = get(n - 1, k - 1);
	cout << (ll)ans << '\n';
}
signed main() {
	ios_base::sync_with_stdio(0); cin.tie(0);
	solve();
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 0 / 60