#324725 (C++14) No.801 エレベーター

• 問題: No.801 エレベーター
• ユーザー: noshi91
• 提出日時: 2019-03-17 21:43:15
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 73 ms / 2,000 ms
• コード長: 6,355 bytes
• コンパイル時間: 726 ms
• コンパイル使用メモリ: 75,588 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-07 21:28:40
• 合計ジャッジ時間: 2,786 ms
• ジャッジサーバーID （参考情報）: judge2 / judge1

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	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	3 ms; 5,376 KB
testcase_04	AC	3 ms; 5,376 KB
testcase_05	AC	3 ms; 5,376 KB
testcase_06	AC	3 ms; 5,376 KB
testcase_07	AC	3 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	3 ms; 5,376 KB
testcase_10	AC	3 ms; 5,376 KB
testcase_11	AC	3 ms; 5,376 KB
testcase_12	AC	3 ms; 5,376 KB
testcase_13	AC	71 ms; 5,376 KB
testcase_14	AC	72 ms; 5,376 KB
testcase_15	AC	71 ms; 5,376 KB
testcase_16	AC	71 ms; 5,376 KB
testcase_17	AC	72 ms; 5,376 KB
testcase_18	AC	71 ms; 5,376 KB
testcase_19	AC	71 ms; 5,376 KB
testcase_20	AC	71 ms; 5,376 KB
testcase_21	AC	72 ms; 5,376 KB
testcase_22	AC	71 ms; 5,376 KB
testcase_23	AC	71 ms; 5,376 KB
testcase_24	AC	71 ms; 5,376 KB
testcase_25	AC	71 ms; 5,376 KB
testcase_26	AC	71 ms; 5,376 KB
testcase_27	AC	71 ms; 5,376 KB
testcase_28	AC	73 ms; 5,376 KB

ソースコード

//#define NDEBUG
#include <cstddef>
#include <cstdint>
#include <vector>

namespace n91 {

	using i8 = std::int_least8_t;
	using i32 = std::int_least32_t;
	using i64 = std::int_least64_t;
	using u8 = std::uint_least8_t;
	using u32 = std::uint_least32_t;
	using u64 = std::uint_least64_t;
	using isize = std::ptrdiff_t;
	using usize = std::size_t;

	class rep {
		const usize f, l;

	public:
		class itr {
			friend rep;
			usize i;
			constexpr itr(const usize x) noexcept : i(x) {}

		public:
			void operator++() noexcept { ++i; }
			constexpr usize operator*() const noexcept { return i; }
			constexpr bool operator!=(const itr x) const noexcept { return i != x.i; }
		};
		constexpr rep(const usize first, const usize last) noexcept
			: f(first), l(last) {}
		constexpr itr begin() const noexcept { return itr(f); }
		constexpr itr end() const noexcept { return itr(l); }
	};
	class revrep {
		const usize f, l;

	public:
		class itr {
			friend revrep;
			usize i;
			constexpr itr(usize x) noexcept : i(x) {}

		public:
			void operator++() noexcept { --i; }
			constexpr usize operator*() const noexcept { return i; }
			constexpr bool operator!=(const itr x) const noexcept { return i != x.i; }
		};
		constexpr revrep(usize first, usize last) noexcept : f(--first), l(--last) {}
		constexpr itr begin() const noexcept { return itr(l); }
		constexpr itr end() const noexcept { return itr(f); }
	};
	template <class T> using vec_alias = std::vector<T>;
	template <class T> auto md_vec(const usize n, const T &value) {
		return std::vector<T>(n, value);
	}
	template <class... Args> auto md_vec(const usize n, Args... args) {
		return std::vector<decltype(md_vec(args...))>(n, md_vec(args...));
	}
	template <class T> constexpr T difference(const T &a, const T &b) {
		return a < b ? b - a : a - b;
	}

} // namespace n91

#include <cassert>
#include <cstdint>

namespace n91 {

	template <std::uint_least32_t Modulus> class modint {
		using u32 = std::uint_least32_t;
		using u64 = std::uint_least64_t;
		using i64 = std::int_fast64_t;
		class optimize_tag_t {};
		static constexpr optimize_tag_t optimize_tag{};

	public:
		using value_type = u32;
		value_type a;

	private:
		static constexpr value_type cst(i64 x) noexcept {
			x %= static_cast<i64>(Modulus);
			if (x < static_cast<i64>(0)) {
				x += static_cast<i64>(Modulus);
			}
			return static_cast<value_type>(x);
		}

		constexpr modint(optimize_tag_t, const value_type &x) noexcept : a(x) {}

	public:
		constexpr modint() noexcept : a(static_cast<value_type>(0)) {}
		constexpr modint(const i64 &x) noexcept : a(cst(x)) {}
		constexpr value_type value() const noexcept { return a; }
		constexpr modint operator+(const modint &o) const noexcept {
			return modint(optimize_tag,
				a + o.a < Modulus ? a + o.a : a + o.a - Modulus);
		}
		constexpr modint operator-(const modint &o) const noexcept {
			return modint(optimize_tag, a < o.a ? a + Modulus - o.a : a - o.a);
		}
		constexpr modint operator*(const modint &o) const noexcept {
			return modint(
				optimize_tag,
				static_cast<value_type>(static_cast<u64>(a) * static_cast<u64>(o.a) %
					static_cast<u64>(Modulus)));
		}
		constexpr modint operator/(const modint &o) const {
			return modint(
				optimize_tag,
				static_cast<value_type>(static_cast<u64>(a) * static_cast<u64>((~o).a) %
					static_cast<u64>(Modulus)));
		}
		modint &operator+=(const modint &o) noexcept {
			if ((a += o.a) >= Modulus)
				a -= Modulus;
			return *this;
		}
		modint &operator-=(const modint &o) noexcept {
			if (a < o.a)
				a += Modulus;
			a -= o.a;
			return *this;
		}
		modint &operator*=(const modint &o) noexcept {
			a = static_cast<value_type>(static_cast<u64>(a) * static_cast<u64>(o.a) %
				static_cast<u64>(Modulus));
			return *this;
		}
		modint &operator/=(const modint &o) {
			a = static_cast<u64>(a) * (~o).a % Modulus;
			return *this;
		}
		constexpr modint inverse() const noexcept {
			assert(a != static_cast<value_type>(0) && "0 does not have inverse");
			return pow(static_cast<u64>(Modulus - static_cast<value_type>(2)));
		}
		constexpr modint operator~() const noexcept { return inverse(); }
		constexpr modint operator-() const noexcept {
			if (a == static_cast<value_type>(0)) {
				return modint(optimize_tag, static_cast<value_type>(0));
			}
			else {
				return modint(optimize_tag, Modulus - a);
			}
		}
		modint &operator++() noexcept {
			if (++a == Modulus) {
				a = static_cast<value_type>(0);
			}
			return *this;
		}
		modint &operator--() noexcept {
			if (a == static_cast<value_type>(0)) {
				a = Modulus;
			}
			--a;
			return *this;
		}
		constexpr bool operator==(const modint &o) const noexcept { return a == o.a; }
		constexpr bool operator!=(const modint &o) const noexcept { return a != o.a; }
		constexpr bool operator<(const modint &o) const noexcept { return a < o.a; }
		constexpr bool operator<=(const modint &o) const noexcept { return a <= o.a; }
		constexpr bool operator>(const modint &o) const noexcept { return a > o.a; }
		constexpr bool operator>=(const modint &o) const noexcept { return a >= o.a; }
		constexpr explicit operator bool() const noexcept { return a; }
		constexpr explicit operator value_type() const noexcept { return a; }
		modint pow(u64 x) const noexcept {
			u64 t = a, u = 1;
			while (x) {
				if (x & 1)
					u = u * t % Modulus;
				t = (t * t) % Modulus;
				x >>= 1;
			}
			return modint(optimize_tag, static_cast<value_type>(u));
		}
	};

} // namespace n91


#include <algorithm>
#include <iostream>
#include <utility>
#include <array>

namespace n91 {

	void main_() {
		using mint = modint<1000000007>;
		usize n, m, k;
		std::cin >> n >> m >> k;
		struct el {
			usize l, r;
		};
		std::vector<el> els(m);
		for (auto &e : els) {
			std::cin >> e.l >> e.r;
			--e.l;
		}
		std::vector<mint> dp(n + 1), prev(n + 1), sum(n + 1);
		dp[0] = 1;
		for (const auto k_cnt : rep(0, k)) {
			std::swap(dp, prev);
			std::fill(dp.begin(), dp.end(), mint(0));
			sum[0] = 0;
			for (const auto i : rep(0, n)) {
				sum[i + 1] = sum[i] + prev[i];
			}
			for (const auto &e : els) {
				const mint s = sum[e.r] - sum[e.l];
				dp[e.l] += s;
				dp[e.r] -= s;
			}
			for (const auto i : rep(0, n)) {
				dp[i + 1] += dp[i];
			}
		}
		std::cout << dp[n - 1].a << std::endl;
	}

} // namespace n91

int main() {
	n91::main_();
	return 0;
}