結果
問題 | No.1554 array_and_me |
ユーザー |
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提出日時 | 2021-06-19 09:33:45 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 59 ms / 2,000 ms |
コード長 | 2,561 bytes |
コンパイル時間 | 930 ms |
コンパイル使用メモリ | 81,172 KB |
最終ジャッジ日時 | 2025-01-22 09:56:46 |
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 * 1 |
other | AC * 41 |
ソースコード
#include <cassert>#include <queue>#include <vector>#include <numeric>#include <iostream>using namespace std;constexpr int M = 998244353;long long modexp(int x, long long e, int m) {long long ans = 1, p = x % m;while (e > 0) {if (e % 2 != 0) ans = (ans * p) % m;p = (p * p) % m;e >>= 1;}return ans;}class ModComb {long long *fact, *facti;const int mod;public:explicit ModComb(int n, int m) : mod(m) {fact = new long long[n+1];facti = new long long[n+1];fact[0] = 1; facti[0] = 1;for (int i = 1; i <= n; i++) fact[i] = (fact[i-1] * i) % m;// calc 1/n!long long &inv = facti[n], pw = fact[n];inv = 1;for (int e = mod-2; e > 0; e /= 2) {if (e&1) inv = inv * pw % mod;pw = pw * pw % mod;}for (int i = n-1; i > 0; i--) facti[i] = (facti[i+1] * (i+1)) % m;}~ModComb() {if (fact) delete[] fact;if (facti) delete[] facti;}long long getFact(int n) const {return fact[n];}long long getFactInv(int n) const {return facti[n];}long long getComb(int n, int k) const {if (n < 0 || k < 0 || k > n) return 0;return fact[n] * facti[k] % mod * facti[n-k] % mod;}long long getPerm(int n, int k) const {if (n < 0 || k < 0 || k > n) return 0;return fact[n] * facti[n-k] % mod;}};int main() {int t; cin >> t;ModComb mc(100100, M);while (t--) {int n, k; cin >> n >> k;vector<int> a(n);for (int i = 0; i < n; i++) cin >> a[i];struct entry {int i, m, a;entry(int i, int m, int a) : i(i), m(m), a(a) {}bool operator<(const entry& rhs) const {return a * rhs.m < rhs.a * m;}};priority_queue<entry> pq;for (int i = 0; i < n; i++) pq.emplace(i, 1, a[i]);vector<int> f(n);int sum = 0;while (sum < k) {auto [i, m, a] = pq.top();pq.pop();sum++;f[i]++;assert(f[i] == m);pq.emplace(i, m+1, a);}long long p = modexp(accumulate(a.begin(), a.end(), 0), M-k-1, M);int s = k;for (int i = 0; i < n; i++) {p = p * mc.getComb(s, f[i]) % M;p = p * modexp(a[i], f[i], M) % M;s -= f[i];}assert(s == 0);cout << p << endl;}}