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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#956736 | #8721. 括号序列 | Andyqian7 | WA | 8ms | 17328kb | C++17 | 4.6kb | 2025-03-29 22:20:50 | 2025-03-29 22:20:51 |
Judging History
answer
#include <bits/stdc++.h>
#define ll long long
#define poly vector<int>
using namespace std;
const int N = 1e6 + 10, P = 998244353;
inline int ksm(int a, int b, int mod)
{
int z = 1;
while (b)
{
if (b & 1)
z = 1ll * z * a % mod;
a = 1ll * a * a % mod;
b >>= 1;
}
return z;
}
namespace Poly
{
const int mod = 998244353, g = 3, invg = 332748118;
int lim, len, rev[N], invlim;
inline void init(int l1, int l2)
{
lim = 1, len = 0;
while (lim <= l1 + l2)
lim <<= 1, len++;
for (int i = 0; i < lim; i++)
rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << (len - 1));
invlim = ksm(lim, mod - 2, mod);
}
inline void NTT(poly &f, int tgpe)
{
for (int i = 0; i < lim; i++)
if (i < rev[i])
swap(f[i], f[rev[i]]);
for (int m = 2; m <= lim; m <<= 1)
{
int wn = ksm(tgpe ? g : invg, (mod - 1) / m, mod);
for (int i = 0; i < lim; i += m)
{
int w = 1;
for (int j = 0; j < m / 2; j++)
{
int u = f[i + j], v = 1ll * w * f[i + j + m / 2] % mod;
f[i + j] = (u + v >= mod ? u + v - mod : u + v), f[i + j + m / 2] = (u - v + mod >= mod ? u - v : u - v + mod);
w = 1ll * wn * w % mod;
}
}
}
if (!tgpe)
{
for (int i = 0; i < lim; i++)
f[i] = 1ll * f[i] * invlim % mod;
}
}
inline void mul(poly &f, poly g)
{
int lf = f.size(), lg = g.size();
init(lf, lg);
f.resize(lim), g.resize(lim);
NTT(f, 1);
NTT(g, 1);
for (int i = 0; i < lim; i++)
f[i] = 1ll * f[i] * g[i] % mod;
NTT(f, 0);
}
}
int n;
poly f;
poly A, B;
int fac[N], ifac[N], inv[N];
void cdq(int l, int r)
{
if (l == r)
{
if (!l)
f[l] = 1;
return;
}
int mid = l + r >> 1;
cdq(l, mid);
if (!l)
{
A.resize(mid - l + 1);
B.resize(mid - l + 1);
for (int i = l; i <= mid; i++)
A[i - l] = 1ll * f[i] * i % P;
for (int i = l; i <= mid; i++)
B[i] = f[i];
int la = A.size(), lb = B.size();
Poly::init(la, lb);
A.resize(Poly::lim), B.resize(Poly::lim);
Poly::NTT(A, 1), Poly::NTT(B, 1);
for (int i = 0; i < Poly::lim; i++)
{
A[i] = 1ll * A[i] % P * B[i] % P;
B[i] = 1ll * B[i] * B[i] % P * B[i] % P;
}
Poly::NTT(A, 0), Poly::NTT(B, 0);
for (int i = mid + 1; i <= r; i++)
f[i] = (f[i] + 1ll * (A[i - l - 1] + B[i - l - 1]) * inv[i]) % P;
}
else
{
A.resize(mid - l + 1);
B.resize(r - l + 1);
for (int i = l; i <= mid; i++)
A[i - l] = 1ll * f[i] * i % P;
for (int i = l; i <= r; i++)
B[i] = f[i];
int la = A.size(), lb = B.size();
Poly::init(la, lb);
A.resize(Poly::lim), B.resize(Poly::lim);
Poly::NTT(A, 1), Poly::NTT(B, 1);
for (int i = 0; i < Poly::lim; i++)
{
A[i] = 1ll * A[i] % P * B[i] % P;
B[i] = 1ll * B[i] * B[i] % P * B[i] % P;
}
Poly::NTT(A, 0), Poly::NTT(B, 0);
for (int i = mid + 1; i <= r; i++)
f[i] = (f[i] + 1ll * (A[i - l - 1] + B[i - l - 1]) * inv[i]) % P;
A.resize(mid - l + 1);
B.resize(r - l + 1);
for (int i = l; i <= mid; i++)
A[i - l] = 1ll * i * f[i];
for (int i = l; i <= r; i++)
B[i] = f[i];
la = A.size(), lb = B.size();
Poly::init(la, lb);
A.resize(Poly::lim), B.resize(Poly::lim);
Poly::NTT(A, 1), Poly::NTT(B, 1);
for (int i = 0; i < Poly::lim; i++)
{
A[i] = 1ll * A[i] % P * B[i] % P;
B[i] = 1ll * B[i] * B[i] % P * B[i] % P;
}
Poly::NTT(A, 0), Poly::NTT(B, 0);
for (int i = mid + 1; i <= r; i++)
f[i] = (f[i] + 1ll * (A[i - l - 1] + B[i - l - 1]) * inv[i]) % P;
}
cdq(mid + 1, r);
}
int main()
{
fac[0] = fac[1] = inv[1] = ifac[0] = ifac[1] = 1;
for (int i = 2; i < N; i++)
{
fac[i] = 1ll * fac[i - 1] * i % P;
inv[i] = 1ll * (P - P / i) * inv[P % i] % P;
ifac[i] = 1ll * ifac[i - 1] * inv[i] % P;
}
scanf("%d", &n);
f.resize(n + 1);
cdq(0, n);
printf("%d", 1ll * f[n] * fac[n] % P);
}
詳細信息
Test #1:
score: 100
Accepted
time: 8ms
memory: 17328kb
input:
3
output:
28
result:
ok 1 number(s): "28"
Test #2:
score: 0
Accepted
time: 7ms
memory: 15520kb
input:
1
output:
1
result:
ok 1 number(s): "1"
Test #3:
score: 0
Accepted
time: 7ms
memory: 16300kb
input:
2
output:
4
result:
ok 1 number(s): "4"
Test #4:
score: -100
Wrong Answer
time: 7ms
memory: 15928kb
input:
4
output:
294
result:
wrong answer 1st numbers differ - expected: '282', found: '294'