結果

問題 No.243 出席番号(2)
ユーザー anta
提出日時 2015-07-10 22:32:23
言語 C++11
(gcc 4.8.5)
結果
AC  
実行時間 157 ms / 2,000 ms
コード長 2,934 Byte
コンパイル時間 514 ms
使用メモリ 1,640 KB
最終ジャッジ日時 2020-05-10 19:27:33

テストケース

テストケース表示
入力 結果 実行時間
使用メモリ
testcase_00 AC 2 ms
1,552 KB
testcase_01 AC 2 ms
1,556 KB
testcase_02 AC 1 ms
1,552 KB
testcase_03 AC 6 ms
1,576 KB
testcase_04 AC 6 ms
1,576 KB
testcase_05 AC 7 ms
1,572 KB
testcase_06 AC 6 ms
1,572 KB
testcase_07 AC 6 ms
1,572 KB
testcase_08 AC 21 ms
1,588 KB
testcase_09 AC 19 ms
1,588 KB
testcase_10 AC 18 ms
1,588 KB
testcase_11 AC 18 ms
1,592 KB
testcase_12 AC 22 ms
1,588 KB
testcase_13 AC 44 ms
1,608 KB
testcase_14 AC 38 ms
1,608 KB
testcase_15 AC 41 ms
1,604 KB
testcase_16 AC 37 ms
1,608 KB
testcase_17 AC 50 ms
1,604 KB
testcase_18 AC 76 ms
1,624 KB
testcase_19 AC 67 ms
1,620 KB
testcase_20 AC 65 ms
1,620 KB
testcase_21 AC 65 ms
1,620 KB
testcase_22 AC 94 ms
1,624 KB
testcase_23 AC 117 ms
1,640 KB
testcase_24 AC 102 ms
1,636 KB
testcase_25 AC 99 ms
1,636 KB
testcase_26 AC 99 ms
1,640 KB
testcase_27 AC 157 ms
1,640 KB
testcase_28 AC 2 ms
1,556 KB
testcase_29 AC 2 ms
1,556 KB
testcase_30 AC 2 ms
1,552 KB
testcase_31 AC 2 ms
1,556 KB
testcase_32 AC 2 ms
1,556 KB
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 #
#include <string>
#include <vector>
#include <algorithm>
#include <numeric>
#include <set>
#include <map>
#include <queue>
#include <iostream>
#include <sstream>
#include <cstdio>
#include <cmath>
#include <ctime>
#include <cstring>
#include <cctype>
#include <cassert>
#include <limits>
#include <functional>
#include <bitset>
#define rep(i,n) for(int (i)=0;(i)<(int)(n);++(i))
#define rer(i,l,u) for(int (i)=(int)(l);(i)<=(int)(u);++(i))
#define reu(i,l,u) for(int (i)=(int)(l);(i)<(int)(u);++(i))
#if defined(_MSC_VER) || __cplusplus > 199711L
#define aut(r,v) auto r = (v)
#else
#define aut(r,v) __typeof(v) r = (v)
#endif
#define each(it,o) for(aut(it, (o).begin()); it != (o).end(); ++ it)
#define all(o) (o).begin(), (o).end()
#define pb(x) push_back(x)
#define mp(x,y) make_pair((x),(y))
#define mset(m,v) memset(m,v,sizeof(m))
#define INF 0x3f3f3f3f
#define INFL 0x3f3f3f3f3f3f3f3fLL
using namespace std;
typedef vector<int> vi; typedef pair<int,int> pii; typedef vector<pair<int,int> > vpii; typedef long long ll;
template<typename T, typename U> inline void amin(T &x, U y) { if(y < x) x = y; }
template<typename T, typename U> inline void amax(T &x, U y) { if(x < y) x = y; }

template<int MOD>
struct ModInt {
	static const int Mod = MOD;
	unsigned x;
	ModInt(): x(0) { }
	ModInt(signed sig) { int sigt = sig % MOD; if(sigt < 0) sigt += MOD; x = sigt; }
	ModInt(signed long long sig) { int sigt = sig % MOD; if(sigt < 0) sigt += MOD; x = sigt; }
	int get() const { return (int)x; }
	
	ModInt &operator+=(ModInt that) { if((x += that.x) >= MOD) x -= MOD; return *this; }
	ModInt &operator-=(ModInt that) { if((x += MOD - that.x) >= MOD) x -= MOD; return *this; }
	ModInt &operator*=(ModInt that) { x = (unsigned long long)x * that.x % MOD; return *this; }
	ModInt &operator/=(ModInt that) { return *this *= that.inverse(); }
	
	ModInt operator+(ModInt that) const { return ModInt(*this) += that; }
	ModInt operator-(ModInt that) const { return ModInt(*this) -= that; }
	ModInt operator*(ModInt that) const { return ModInt(*this) *= that; }
	ModInt operator/(ModInt that) const { return ModInt(*this) /= that; }
	
	ModInt inverse() const {
		signed a = x, b = MOD, u = 1, v = 0;
		while(b) {
			signed t = a / b;
			a -= t * b; std::swap(a, b);
			u -= t * v; std::swap(u, v);
		}
		if(u < 0) u += Mod;
		ModInt res; res.x = (unsigned)u;
		return res;
	}
};
typedef ModInt<1000000007> mint;

int main() {
	int N;
	while(cin >> N) {
		vi A(N);
		rep(i, N) cin >> A[i];
		vi cnt(N, 0);
		rep(i, N) if(A[i] < N)
			++ cnt[A[i]];
		vector<mint> dp(N+2), ndp;
		dp[0] = 1;
		rep(i, N) {
			ndp.assign(N+2, mint());
			rer(j, 0, N) {
				mint x = dp[j];
				if(x.get() == 0) continue;
				ndp[j] += x;
				ndp[j+1] += x * cnt[i];
			}
			dp.swap(ndp);
		}
		mint ans;
		rer(j, 0, N) {
			mint x = dp[j];
			rep(k, N - j) x *= N - j - k;
			if(j % 2 == 0) ans += x; else ans -= x;
		}
		printf("%d\n", ans.get());
	}
	return 0;
}
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