-
Notifications
You must be signed in to change notification settings - Fork 3
/
HDU5730.cpp
102 lines (95 loc) · 2.15 KB
/
HDU5730.cpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
#include <cmath>
#include <cstdio>
#include <cstring>
#include <algorithm>
#define MAXN 1<<18
#define MOD 313
using namespace std;
const double pi = acos(-1.0);
struct Complex
{
double a, b;
Complex() {}
Complex(double _, double __): a(_), b(__) {}
inline Complex operator + (const Complex &z)const
{
return Complex(a + z.a, b + z.b);
}
inline Complex operator - (const Complex &z)const
{
return Complex(a - z.a, b - z.b);
}
inline Complex operator * (const Complex &z)const
{
return Complex(a * z.a - b * z.b, a * z.b + b * z.a);
}
};
Complex a[MAXN], b[MAXN];
int n, m, L, dp[MAXN], v[MAXN], rev[MAXN];
inline void FFT(Complex c[], int n, int f)
{
Complex w, wn, x, y;
for (int i = 0; i < n; i++)
if (i < rev[i]) swap(c[i], c[rev[i]]);
for (int i = 1; i < n; i <<= 1)
{
wn = Complex(cos(pi / i), sin(pi / i) * f);
for (int p = i << 1, j = 0; j < n; j += p)
{
w = Complex(1, 0);
for (int k = 0; k < i; k++, w = w * wn)
{
x = c[j + k];
y = w * c[j + k + i];
c[j + k] = x + y;
c[j + k + i] = x - y;
}
}
}
if (!~f)
for (int i = 0; i < n; i++) c[i].a /= (double)n;
return ;
}
inline void CDQ(int l, int r)
{
if (l == r)
{
dp[l] = (dp[l] + v[l]) % MOD;
return ;
}
int mid = (l + r) >> 1;
CDQ(l, mid);
for (m = 1, L = 0; m <= r - l + 1; m <<= 1, L++);
for (int i = 0; i < m; i++) rev[i] = (rev[i >> 1] >> 1) | ((i & 1) << (L - 1));
for (int i = 0; i < m; i++) a[i] = b[i] = Complex(0, 0);
for (int i = l; i <= mid; i++) a[i - l] = Complex(dp[i], 0);
for (int i = 0; i < r - l + 1; i++) b[i] = Complex(v[i + 1], 0);
FFT(a, m, 1);
FFT(b, m, 1);
for (int i = 0; i < m; i++) a[i] = a[i] * b[i];
FFT(a, m, -1);
for (int i = mid + 1; i <= r; i++) dp[i] += (int)(a[i - l - 1].a + 0.5), dp[i] %= MOD;
CDQ(mid + 1, r);
return ;
}
inline void read(int &x)
{
x = 0;
char ch = getchar();
while (ch < '0' || ch > '9') ch = getchar();
while (ch >= '0' && ch <= '9') x = (x << 3) + (x << 1) + ch - '0', ch = getchar();
return ;
}
int main()
{
while (true)
{
read(n);
if (!n) break;
memset(dp, 0, sizeof dp);
for (int i = 1; i <= n; i++) read(v[i]), v[i] %= MOD;
CDQ(1, n);
printf("%d\n", dp[n]);
}
return 0;
}