結果
問題 | No.1035 Color Box |
ユーザー |
|
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 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 36 |
ソースコード
#include <iostream>#include <vector>template <int MOD>struct ModInt {using lint = long long;int val;// constructorModInt(lint v = 0) : val(v % MOD) {if (val < 0) val += MOD;};// unary operatorModInt operator+() const { return ModInt(val); }ModInt operator-() const { return ModInt(MOD - val); }ModInt inv() const { return this->pow(MOD - 2); }// arithmeticModInt 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 assignmentModInt& 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(); }// comparebool operator==(const ModInt& b) const { return val == b.val; }bool operator!=(const ModInt& b) const { return val != b.val; }// I/Ofriend 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;}