提交记录 16741


用户 题目 状态 得分 用时 内存 语言 代码长度
Saisyc 1002. 测测你的多项式乘法 Time Limit Exceeded 0 5 s 8 KB C++ 1.07 KB
提交时间 评测时间
2021-10-18 00:38:16 2021-10-18 00:38:22
#include <algorithm>

const int N =     1 << 21;
const int p =    81 << 21 | 1;
const int g =  1167 << 12 | 1;
const int h = 11443 << 12 | 1;

inline int pow_modp(int a, int b) { int x = 1; for(; b; a = (long long)a * a % p, b >>= 1) if(b & 1) x = (long long)x * a % p; return x; }

unsigned ntt_sup[N];
inline void ntt(auto a[], int n, const int g) {
	auto b = ntt_sup, j = a, _j = a; int _n = n >> 1, i, k, _k, w, _w;
	for(i = 1, w = pow_modp(g, (p - 1) / n); i < n; i <<= 1, w = (long long)w * w % p, std :: swap(a, b))
		for(k = 0, j = a, _j = a + _n, _w = 1; k != n; k += i, _w = (long long)_w * w % p)
			for(_k = k, k += i; _k != k; ++j, ++_j, ++_k);
//				b[_k] = *j + *_j < p ? *j + *_j : *j + *_j - p,
//				b[_k + i] = (long long)(*j + p - *_j) * _w % p;
	if(b != ntt_sup) std :: copy(a, a + n, b);
}

void poly_multiply(unsigned *a, int n, unsigned *b, int m, unsigned *c) {
	ntt(a, n, g), ntt(b, n, g);     for(int i = 0; i < n; ++i) a[i] = (long long)a[i] * b[i] % p; ntt(a, n, h);
	int inv_n = pow_modp(n, p - 2); for(int i = 0; i < n; ++i) c[i] = (long long)a[i] * inv_n % p;
}

CompilationN/AN/ACompile OKScore: N/A

Testcase #15 s8 KBTime Limit ExceededScore: 0


Judge Duck Online | 评测鸭在线
Server Time: 2026-03-18 17:52:47 | Loaded in 1 ms | Server Status
个人娱乐项目,仅供学习交流使用 | 捐赠