답안 #520036

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
520036 2022-01-28T07:57:15 Z KoD Zapina (COCI20_zapina) C++17
110 / 110
87 ms 320 KB
#include <bits/stdc++.h>

using std::vector;
using std::array;
using std::pair;
using std::tuple;

constexpr int MOD = 1000000007;

struct Fp {
    int x;
    Fp(int x = 0) : x(x) {}
    Fp& operator+=(const Fp& t) {
        if ((x += t.x) >= MOD) x -= MOD;
        return *this;
    }
    Fp& operator-=(const Fp& t) {
        if ((x -= t.x) < 0) x += MOD;
        return *this;
    }
    Fp& operator*=(const Fp& t) {
        x = (long long)x * t.x % MOD;
        return *this;
    }
    Fp operator+(const Fp& t) const {
        return Fp(*this) += t;
    }
    Fp operator-(const Fp& t) const {
        return Fp(*this) -= t;
    }
    Fp operator*(const Fp& t) const {
        return Fp(*this) *= t;
    }
    Fp pow(int e) const {
        Fp ret(1), mul(*this);
        while (e > 0) {
            if (e & 1) ret *= mul;
            mul *= mul;
            e >>= 1;
        }
        return ret;
    }
    Fp inv() const {
        return pow(MOD - 2);
    }
};

int main() {
    std::ios_base::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int N;
    std::cin >> N;
    vector<Fp> fact(N + 1), inv_fact(N + 1);
    fact[0] = 1;
    for (int i = 1; i <= N; ++i) {
        fact[i] = fact[i - 1] * i;
    }
    inv_fact[N] = fact[N].inv();
    for (int i = N; i >= 1; --i) {
        inv_fact[i - 1] = inv_fact[i] * i;
    }
    vector<Fp> dp(N + 1);
    dp[0] = 1;
    for (int i = 1; i <= N; ++i) {
        vector<Fp> next(N + 1);
        for (int j = 0; j <= N; ++j) {
            for (int k = 0; k <= j; ++k) {
                if (k != i) {
                    next[j] += dp[j - k] * inv_fact[k];
                }
            }
        }
        dp = std::move(next);
    }
    std::cout << (Fp(N).pow(N) - fact[N] * dp[N]).x << '\n';
    return 0;
}
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 308 KB Output is correct
10 Correct 0 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 4 ms 204 KB Output is correct
14 Correct 1 ms 312 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 204 KB Output is correct
2 Correct 1 ms 204 KB Output is correct
3 Correct 0 ms 204 KB Output is correct
4 Correct 0 ms 204 KB Output is correct
5 Correct 1 ms 204 KB Output is correct
6 Correct 0 ms 204 KB Output is correct
7 Correct 1 ms 204 KB Output is correct
8 Correct 1 ms 204 KB Output is correct
9 Correct 1 ms 308 KB Output is correct
10 Correct 0 ms 204 KB Output is correct
11 Correct 1 ms 204 KB Output is correct
12 Correct 1 ms 204 KB Output is correct
13 Correct 4 ms 204 KB Output is correct
14 Correct 1 ms 312 KB Output is correct
15 Correct 1 ms 204 KB Output is correct
16 Correct 1 ms 204 KB Output is correct
17 Correct 41 ms 204 KB Output is correct
18 Correct 1 ms 308 KB Output is correct
19 Correct 9 ms 320 KB Output is correct
20 Correct 1 ms 204 KB Output is correct
21 Correct 54 ms 204 KB Output is correct
22 Correct 6 ms 204 KB Output is correct
23 Correct 1 ms 204 KB Output is correct
24 Correct 12 ms 204 KB Output is correct
25 Correct 10 ms 204 KB Output is correct
26 Correct 16 ms 312 KB Output is correct
27 Correct 82 ms 316 KB Output is correct
28 Correct 78 ms 296 KB Output is correct
29 Correct 78 ms 292 KB Output is correct
30 Correct 86 ms 292 KB Output is correct
31 Correct 87 ms 204 KB Output is correct
32 Correct 82 ms 204 KB Output is correct
33 Correct 80 ms 304 KB Output is correct
34 Correct 86 ms 204 KB Output is correct
35 Correct 85 ms 204 KB Output is correct
36 Correct 82 ms 204 KB Output is correct
37 Correct 82 ms 296 KB Output is correct