結果

問題 No.856 増える演算
ユーザー QCFium
提出日時 2019-10-08 18:03:45
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
WA  
実行時間 -
コード長 3,089 bytes
コンパイル時間 2,186 ms
コンパイル使用メモリ 182,944 KB
実行使用メモリ 12,172 KB
最終ジャッジ日時 2024-11-07 08:24:47
合計ジャッジ時間 16,521 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 47 WA * 33
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ソースコード

diff #
プレゼンテーションモードにする

#include <bits/stdc++.h>
int ri() {
    int n;
    scanf("%d", &n);
    return n;
}
int pow(int a, int b, int mod) {
    int res = 1;
    for (; b; b >>= 1) {
        if (b & 1) res = (int64_t) res * a % mod;
        a = (int64_t) a * a % mod;
    }
    return res;
}
int inv(int i, int mod) { return pow(i, mod - 2, mod); }
template<int mod, int proot> struct NTT {
    int get_mod() { return mod; }
    void ntt(std::vector<int> &a, bool inverse) {
        int n = a.size();
        assert((n & -n) == n);
        int h = pow(proot, (mod - 1) / n, mod);
        if (inverse) h = inv(h, mod);
        
        for (int i = 0, j = 1; j < n - 1; j++) {
            for (int k = n >> 1; k > (i ^= k); k >>= 1);
            if (j < i) std::swap(a[i], a[j]);
        }
        for (int i = 1; i < n; i <<= 1) {
            int base = pow(h, n / i / 2, mod);
            int w = 1;
            for (int j = 0; j < i; j++) {
                for (int k = j; k < n; k += i << 1) {
                    int u = a[k];
                    int d = (int64_t) a[k + i] * w % mod;
                    a[k] = u + d;
                    if (a[k] >= mod) a[k] -= mod;
                    a[k + i] = u - d;
                    if (a[k + i] < 0) a[k + i] += mod;
                }
                w = (int64_t) w * base % mod;
            }
        }
        if (inverse) {
            int ninv = inv(a.size(), mod);
            for (auto &i : a) i = (int64_t) i * ninv % mod;
        }
    }
    std::vector<int> conv(const std::vector<int> a_, const std::vector<int> b_) {
        std::vector<int> a = a_, b = b_;
        size_t size = 1;
        for (; size < a_.size() + b_.size(); size <<= 1);
        a.resize(size);
        b.resize(size);
        ntt(a, false);
        ntt(b, false);
        for (size_t i = 0; i < size; i++) a[i] = (int64_t) a[i] * b[i] % mod;
        ntt(a, true);
        a.resize(a_.size() + b_.size() - 1);
        return a;
    }
};
#define MOD 1000000007
std::vector<int64_t> conv(const std::vector<int> a, const std::vector<int> b) {
    NTT<998244353, 3> ntt1;
    NTT<469762049, 3> ntt2;
    auto r0 = ntt1.conv(a, b);
    auto r1 = ntt2.conv(a, b);
    int n = r0.size();
    std::vector<int64_t> res;
    for (int i = 0; i < n; i++) {
        int64_t cur = r0[i];
        while (cur % 469762049 != r1[i]) cur += 998244353;
        res.push_back(cur);
    }
    return res;
}
int main() {
    int n = ri();
    int a[n];
    for (int i = 0; i < n; i++) a[i] = ri();
    
    std::multiset<std::pair<int, int> > all;
    for (int i = 0; i < n; i++) all.insert({a[i], i});
    std::pair<int, int> optimal;
    double min = 1000000000;
    for (int i = 0; i < n; i++) {
        all.erase(all.find({a[i], i}));
        double cur = log(a[i]) * all.begin()->first;
        if (min > cur) min = cur, optimal = {i, all.begin()->second};
    }
    
    int64_t sum[n];
    sum[n - 1] = 0;
    for (int i = n - 2; i >= 0; i--) sum[i] = sum[i + 1] + a[i + 1];
    int res = 1;
    for (int i = 0; i < n; i++) res = (int64_t) res * pow(a[i], sum[i] % (MOD - 1), MOD) % MOD;
    
    std::vector<int> num(100001);
    for (int i = 0; i < n; i++) num[a[i]]++;
    auto conved = conv(num, num);
    for (int i = 0; i < n; i++) conved[a[i] + a[i]]--;
    for (int i = 1; i <= 200000; i++) assert(conved[i] % 2 == 0), conved[i] >>= 1, res = (int64_t) res * pow(i, conved[i] % (MOD - 1), MOD) % MOD;
    res = (int64_t) res * inv((int64_t) (a[optimal.first] + a[optimal.second]) * pow(a[optimal.first], a[optimal.second], MOD) % MOD, MOD) % MOD;
    
    std::cout << res << std::endl;
    
    return 0;
}
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