結果

問題 No.823 Many Shifts Easy
ユーザー firiexpfiriexp
提出日時 2019-04-26 22:22:19
言語 C++14
(gcc 12.3.0 + boost 1.83.0)
結果
CE  
(最新)
AC  
(最初)
実行時間 -
コード長 2,041 bytes
コンパイル時間 638 ms
コンパイル使用メモリ 86,616 KB
最終ジャッジ日時 2024-11-14 21:25:53
合計ジャッジ時間 1,053 ms
ジャッジサーバーID
(参考情報)
judge2 / judge3
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コンパイルメッセージ
main.cpp:17:39: error: '::numeric_limits' has not been declared
   17 | template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;
      |                                       ^~~~~~~~~~~~~~
main.cpp:17:55: error: expected primary-expression before '>' token
   17 | template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;
      |                                                       ^
main.cpp:17:61: error: no matching function for call to 'max()'
   17 | template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;
      |                                                        ~~~~~^~
In file included from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/string:50,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/locale_classes.h:40,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/ios_base.h:41,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/ios:42,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/ostream:38,
                 from /home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/iostream:39,
                 from main.cpp:1:
/home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_algobase.h:254:5: note: candidate: 'template<class _Tp> constexpr const _Tp& std::max(const _Tp&, const _Tp&)'
  254 |     max(const _Tp& __a, const _Tp& __b)
      |     ^~~
/home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_algobase.h:254:5: note:   template argument deduction/substitution failed:
main.cpp:17:61: note:   candidate expects 2 arguments, 0 provided
   17 | template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;
      |                                                        ~~~~~^~
/home/linuxbrew/.linuxbrew/Cellar/gcc@12/12.3.0/include/c++/12/bits/stl_algobase.h:300:5: note: candidate: 'templat

ソースコード

diff #

#include <iostream>
#include <algorithm>
#include <iomanip>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <numeric>
#include <bitset>
#include <cmath>

static const int MOD = 1000000007;
using ll = long long;
using u32 = uint32_t;
using namespace std;

template<class T> constexpr T INF = ::numeric_limits<T>::max()/32*15+208;

template <class T>
T pow_ (T x, T n, T M){
    uint64_t u = 1, xx = x;
    while (n > 0){
        if (n&1) u = u * xx % M;
        xx = xx * xx % M;
        n >>= 1;
    }
    return static_cast<T>(u);
};

template <class T> class Factorial {
    T mod;
    vector<uint64_t> facts, factinv;

public:
    Factorial(int n, T mod) : facts(static_cast<u32>(n+1)), factinv(static_cast<u32>(n+1)), mod(mod) {
        facts[0] = 1;
        for (int i = 1; i < n+1; ++i) facts[i] = facts[i-1]*i % mod;
        factinv[n] = pow_(facts[n], static_cast<uint64_t>(mod - 2), static_cast<uint64_t>(mod));
        for (int i = n-1; i >= 0; --i) factinv[i] = factinv[i+1] * (i+1) % mod;
    }

    T fact(int k) const {
        if(k >= 0) return static_cast<T>(facts[k]);
        else return static_cast<T>(factinv[-k]);
    }

    T operator[](const int &k) const {
        if(k >= 0) return static_cast<T>(facts[k]);
        else return static_cast<T>(factinv[-k]);
    }

    T C(int p, int q) const {
        if(q < 0 || p < q) return 0;
        return static_cast<T>(facts[p]*  factinv[q] % mod * factinv[p-q] % mod);
    }

    T P(int p, int q) const {
        if(q < 0 || p < q) return 0;
        return static_cast<T>((facts[p] * factinv[p-q]) % mod);
    }

    T H(int p, int q) const {
        if(p < 0 || q < 0) return 0;
        return static_cast<T>(q == 0 ? 1 : C(p+q-1, q));
    }
};

int main() {
    ll n, k;
    cin >> n >> k;
    ll ans = 0;
    Factorial<ll> f(n, MOD);
    ll q = f.P(n-1, k);
    for (int i = n; i >= 1; --i) {
        ll p = i;
        (ans += p*q) %= MOD;
        if(i == n) (q += f.P(n-2, k-2)*f.C(k, 2)) %= MOD;
    }
    cout << ans << "\n";
    return 0;
}
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