結果
| 問題 |
No.2926 Botaoshi
|
| コンテスト | |
| ユーザー |
|
| 提出日時 | 2024-10-23 18:12:12 |
| 言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
| 結果 |
AC
|
| 実行時間 | 5 ms / 2,000 ms |
| コード長 | 8,617 bytes |
| コンパイル時間 | 920 ms |
| コンパイル使用メモリ | 72,816 KB |
| 最終ジャッジ日時 | 2025-02-24 22:27:48 |
|
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 4 |
| other | AC * 42 |
ソースコード
#include <iostream>
#include <cstdint>
#include <vector>
using namespace std;
template<unsigned int MOD> class mod_int
{
private:
unsigned int value = 0;
constexpr static bool is_prime(const unsigned int arg) noexcept
{
for (unsigned int i = 2; i * i <= arg; ++i)
if (arg % i == 0) return false;
return true;
}
constexpr static unsigned int pow_mod(unsigned int a, size_t b) noexcept
{
if (MOD == 1) return 0;
unsigned int ans = 1;
a %= MOD;
for (; b != 0; b >>= 1, a = static_cast<unsigned long long>(a) * a % MOD)
if (b & 1) ans = ans * static_cast<unsigned long long>(a) % MOD;
return ans;
}
public:
constexpr mod_int() noexcept { static_assert(MOD != 0, "0 cannot be set as \'MOD.\'"); }
template<typename T> constexpr mod_int(const T arg) noexcept { static_assert(MOD != 0, "0 cannot be set as \'MOD.\'"); value = (unsigned int)(arg % MOD); }
constexpr mod_int<MOD> operator+(const mod_int<MOD> other) const noexcept { return mod_int(this->value >= MOD - other.value ? this->value - (MOD - other.value) : this->value + other.value); }
constexpr mod_int<MOD> operator-(const mod_int<MOD> other) const noexcept { return mod_int(this->value >= other.value ? this->value - other.value : MOD - (other.value - this->value)); }
constexpr mod_int<MOD> operator*(const mod_int<MOD> other) const noexcept { if constexpr (MOD >= (1u << 16)) return mod_int(static_cast<unsigned long long>(this->value) * other.value % MOD); else return mod_int(this->value * other.value % MOD); }
constexpr mod_int<MOD> operator/(const mod_int<MOD> other) const noexcept { static_assert(is_prime(MOD), "\'MOD\' is not a prime number."); if constexpr (MOD >= (1u << 16)) return mod_int(static_cast<unsigned long long>(this->value) * pow_mod(other.value, MOD - 2) % MOD); else return mod_int(this->value * pow_mod(other.value, MOD - 2) % MOD); }
template<typename T> constexpr mod_int<MOD> operator+(T arg) const noexcept { arg %= MOD; return mod_int(value >= MOD - static_cast<unsigned int>(arg) ? value - (MOD - static_cast<unsigned int>(arg)) : value + static_cast<unsigned int>(arg)); }
template<typename T> constexpr mod_int<MOD> operator-(T arg) const noexcept { arg %= MOD; return mod_int(value >= static_cast<unsigned int>(arg) ? value - static_cast<unsigned int>(arg) : MOD - (static_cast<unsigned int>(arg) - value)); }
template<typename T> constexpr mod_int<MOD> operator*(T arg) const noexcept { if constexpr (MOD >= (1u << 16)) return mod_int(static_cast<unsigned long long>(value) * (arg % MOD) % MOD); else return mod_int(value * static_cast<unsigned int>(arg % MOD) % MOD); }
template<typename T> constexpr mod_int<MOD> operator/(T arg) const noexcept { static_assert(is_prime(MOD), "\'MOD\' is not a prime number."); if constexpr (MOD >= (1u << 16)) return mod_int(static_cast<unsigned long long>(value) * pow_mod(static_cast<unsigned int>(arg % MOD), MOD - 2) % MOD); else return mod_int(value * pow_mod(static_cast<unsigned int>(arg % MOD), MOD - 2) % MOD); }
constexpr mod_int<MOD>& operator+=(const mod_int<MOD> other) noexcept { if (this->value >= MOD - other.value) this->value -= (MOD - other.value); else this->value += other.value; return *this; }
constexpr mod_int<MOD>& operator-=(const mod_int<MOD> other) noexcept { if (this->value >= other.value) this->value -= other.value; else this->value += (MOD - other.value); return *this; }
constexpr mod_int<MOD>& operator*=(const mod_int<MOD> other) noexcept { if constexpr (MOD >= (1u << 16)) this->value = static_cast<unsigned long long>(this->value) * other.value % MOD; else this->value = this->value * other.value % MOD; return *this; }
constexpr mod_int<MOD>& operator/=(const mod_int<MOD> other) noexcept { static_assert(is_prime(MOD), "\'MOD\' is not a prime number."); if constexpr (MOD >= (1u << 16)) this->value = static_cast<unsigned long long>(this->value) * pow_mod(other.value, MOD - 2) % MOD; else this->value = this->value * pow_mod(other.value, MOD - 2) % MOD; return *this; }
template<typename T> constexpr mod_int<MOD>& operator+=(T arg) noexcept { arg %= MOD; if (value >= MOD - arg) value -= (MOD - arg); else value += arg; return *this; }
template<typename T> constexpr mod_int<MOD>& operator-=(T arg) noexcept { arg %= MOD; if (value >= arg) value -= arg; else value += (MOD - arg); return *this; }
template<typename T> constexpr mod_int<MOD>& operator*=(T arg) noexcept { if constexpr (MOD >= (1u << 16)) value = static_cast<unsigned long long>(value) * (arg % MOD) % MOD; else value = value * (arg % MOD) % MOD; return *this; }
template<typename T> constexpr mod_int<MOD>& operator/=(T arg) noexcept { static_assert(is_prime(MOD), "\'MOD\' is not a prime number."); if constexpr (MOD >= (1u << 16)) value = static_cast<unsigned long long>(value) * pow_mod(static_cast<unsigned int>(arg % MOD), MOD - 2) % MOD; else value = value * pow_mod(static_cast<unsigned int>(arg % MOD), MOD - 2) % MOD; return *this; }
constexpr mod_int<MOD>& operator++() noexcept { if (value + 1 == MOD) value = 0; else ++value; return *this; }
constexpr mod_int<MOD> operator++(int) noexcept { const auto temp = value; if (value + 1 == MOD) value = 0; else ++value; return mod_int<MOD>(temp); }
constexpr mod_int<MOD>& operator--() noexcept { if (value == 0) value = MOD - 1; else --value; return *this; }
constexpr mod_int<MOD> operator--(int) noexcept { const auto temp = value; if (value == 0) value = MOD - 1; else --value; return *this; }
constexpr bool operator==(const mod_int<MOD> other) const noexcept { return this->value == other.value; }
constexpr bool operator!=(const mod_int<MOD> other) const noexcept { return this->value != other.value; }
constexpr bool operator<(const mod_int<MOD> other) const noexcept { return this->value < other.value; }
constexpr bool operator<=(const mod_int<MOD> other) const noexcept { return this->value <= other.value; }
constexpr bool operator>(const mod_int<MOD> other) const noexcept { return this->value > other.value; }
constexpr bool operator>=(const mod_int<MOD> other) const noexcept { return this->value >= other.value; }
template<typename T> constexpr bool operator==(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value == arg; }
template<typename T> constexpr bool operator!=(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value != arg; }
template<typename T> constexpr bool operator<(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value < arg; }
template<typename T> constexpr bool operator<=(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value <= arg; }
template<typename T> constexpr bool operator>(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value > arg; }
template<typename T> constexpr bool operator>=(const T arg) const noexcept { static_assert(is_integral<T>::value, "T is not an integral type."); return value >= arg; }
operator unsigned int() const noexcept { return this->value; }
constexpr mod_int<MOD> pow_mod(unsigned long long times)
{
if (MOD == 1) return 0;
mod_int<MOD> ans = 1;
unsigned int a = this->value;
for (; times != 0; times >>= 1, a = static_cast<unsigned long long>(a) * a % MOD)
if (times & 1) ans.value = static_cast<unsigned long long>(ans.value) * a % MOD;
return ans;
}
};
int main()
{
cin.tie(nullptr);
ios::sync_with_stdio(false);
uint32_t N, i;
cin >> N;
string S;
S.reserve(N), cin >> S;
mod_int<998244353> dp[2][3];
switch (S[0])
{
case 'L':
dp[1][0] = 1, dp[1][1] = dp[1][2] = 0;
break;
case 'R':
dp[1][1] = 1, dp[1][0] = dp[1][2] = 0;
break;
case 'U':
dp[1][2] = 1, dp[1][0] = dp[1][1] = 0;
break;
case '.':
dp[1][0] = dp[1][1] = dp[1][2] = 1;
break;
}
for (i = 1; i != N; ++i)
{
switch (S[i])
{
case 'L':
dp[(i & 1) ^ 1][0] = dp[i & 1][0] + dp[i & 1][2];
dp[(i & 1) ^ 1][1] = dp[(i & 1) ^ 1][2] = 0;
break;
case 'R':
dp[(i & 1) ^ 1][1] = dp[i & 1][0] + dp[i & 1][1] + dp[i & 1][2];
dp[(i & 1) ^ 1][0] = dp[(i & 1) ^ 1][2] = 0;
break;
case 'U':
dp[(i & 1) ^ 1][2] = dp[i & 1][0] + dp[i & 1][1] + dp[i & 1][2];
dp[(i & 1) ^ 1][0] = dp[(i & 1) ^ 1][1] = 0;
break;
case '.':
dp[(i & 1) ^ 1][0] = dp[i & 1][0] + dp[i & 1][2];
dp[(i & 1) ^ 1][1] = dp[(i & 1) ^ 1][2] = dp[i & 1][0] + dp[i & 1][1] + dp[i & 1][2];
break;
}
}
cout << dp[N & 1][0] + dp[N & 1][1] + dp[N & 1][2] << '\n';
return 0;
}