結果

問題 No.1035 Color Box
ユーザー Mister
提出日時 2020-05-01 11:37:31
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 26 ms / 2,000 ms
コード長 2,869 bytes
コンパイル時間 1,222 ms
コンパイル使用メモリ 73,456 KB
最終ジャッジ日時 2025-01-10 03:56:50
ジャッジサーバーID
(参考情報)
judge5 / judge3
このコードへのチャレンジ
(要ログイン)
ファイルパターン 結果
sample AC * 2
other AC * 36
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

#include <iostream>
#include <vector>
template <int MOD>
struct ModInt {
using lint = long long;
int val;
// constructor
ModInt(lint v = 0) : val(v % MOD) {
if (val < 0) val += MOD;
};
// unary operator
ModInt operator+() const { return ModInt(val); }
ModInt operator-() const { return ModInt(MOD - val); }
ModInt inv() const { return this->pow(MOD - 2); }
// arithmetic
ModInt operator+(const ModInt& x) const { return ModInt(*this) += x; }
ModInt operator-(const ModInt& x) const { return ModInt(*this) -= x; }
ModInt operator*(const ModInt& x) const { return ModInt(*this) *= x; }
ModInt operator/(const ModInt& x) const { return ModInt(*this) /= x; }
ModInt pow(lint n) const {
auto x = ModInt(1);
auto b = *this;
while (n > 0) {
if (n & 1) x *= b;
n >>= 1;
b *= b;
}
return x;
}
// compound assignment
ModInt& operator+=(const ModInt& x) {
if ((val += x.val) >= MOD) val -= MOD;
return *this;
}
ModInt& operator-=(const ModInt& x) {
if ((val -= x.val) < 0) val += MOD;
return *this;
}
ModInt& operator*=(const ModInt& x) {
val = lint(val) * x.val % MOD;
return *this;
}
ModInt& operator/=(const ModInt& x) { return *this *= x.inv(); }
// compare
bool operator==(const ModInt& b) const { return val == b.val; }
bool operator!=(const ModInt& b) const { return val != b.val; }
// I/O
friend std::istream& operator>>(std::istream& is, ModInt& x) noexcept { return is >> x.val; }
friend std::ostream& operator<<(std::ostream& os, const ModInt& x) noexcept { return os << x.val; }
};
template <class T>
struct Combination {
int max_n;
std::vector<T> f, invf;
explicit Combination(int n)
: max_n(n), f(n + 1), invf(n + 1) {
f[0] = 1;
for (int i = 1; i <= n; ++i) {
f[i] = f[i - 1] * i;
}
invf[max_n] = f[max_n].inv();
for (int i = max_n - 1; i >= 0; --i) {
invf[i] = invf[i + 1] * (i + 1);
}
}
T fact(int n) const { return f[n]; }
T invfact(int n) const { return invf[n]; }
T perm(int a, int b) const {
return a < b || b < 0 ? T(0) : f[a] * invf[a - b];
}
T comb(int a, int b) const {
return a < b || b < 0 ? T(0) : f[a] * invf[a - b] * invf[b];
}
};
constexpr int MOD = 1e9 + 7;
using mint = ModInt<MOD>;
const Combination<mint> C(100000);
void solve() {
int n, m;
std::cin >> n >> m;
mint ans = 0;
for (int i = 0; i <= m; ++i) {
ans += mint(m - i).pow(n) * C.comb(m, i) * mint(-1).pow(i);
}
std::cout << ans << std::endl;
}
int main() {
std::cin.tie(nullptr);
std::ios::sync_with_stdio(false);
solve();
return 0;
}
הההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההההה
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
0