結果
| 問題 |
No.2720 Sum of Subarray of Subsequence of...
|
| コンテスト | |
| ユーザー |
|
| 提出日時 | 2024-03-11 18:37:16 |
| 言語 | PyPy3 (7.3.15) |
| 結果 |
AC
|
| 実行時間 | 1,555 ms / 4,000 ms |
| コード長 | 6,838 bytes |
| コンパイル時間 | 302 ms |
| コンパイル使用メモリ | 82,556 KB |
| 実行使用メモリ | 201,808 KB |
| 最終ジャッジ日時 | 2024-10-01 01:29:36 |
| 合計ジャッジ時間 | 18,799 ms |
|
ジャッジサーバーID (参考情報) |
judge3 / judge5 |
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| ファイルパターン | 結果 |
|---|---|
| sample | AC * 2 |
| other | AC * 31 |
ソースコード
# https://judge.yosupo.jp/submission/55648 より拝借
########################### ここから ###########################
# AtCoder Libary v1.4 を python に移植したもの
# https://github.com/atcoder/ac-library/blob/master/atcoder/convolution.hpp
MOD = 998244353
IMAG = 911660635
IIMAG = 86583718
rate2 = (0, 911660635, 509520358, 369330050, 332049552, 983190778, 123842337, 238493703, 975955924, 603855026, 856644456, 131300601, 842657263, 730768835, 942482514, 806263778, 151565301, 510815449, 503497456, 743006876, 741047443, 56250497, 867605899, 0)
irate2 = (0, 86583718, 372528824, 373294451, 645684063, 112220581, 692852209, 155456985, 797128860, 90816748, 860285882, 927414960, 354738543, 109331171, 293255632, 535113200, 308540755, 121186627, 608385704, 438932459, 359477183, 824071951, 103369235, 0)
rate3 = (0, 372528824, 337190230, 454590761, 816400692, 578227951, 180142363, 83780245, 6597683, 70046822, 623238099, 183021267, 402682409, 631680428, 344509872, 689220186, 365017329, 774342554, 729444058, 102986190, 128751033, 395565204, 0)
irate3 = (0, 509520358, 929031873, 170256584, 839780419, 282974284, 395914482, 444904435, 72135471, 638914820, 66769500, 771127074, 985925487, 262319669, 262341272, 625870173, 768022760, 859816005, 914661783, 430819711, 272774365, 530924681, 0)
def butterfly(a):
n = len(a)
h = (n - 1).bit_length()
le = 0
while le < h:
if h - le == 1:
p = 1 << (h - le - 1)
rot = 1
for s in range(1 << le):
offset = s << (h - le)
for i in range(p):
l = a[i + offset]
r = a[i + offset + p] * rot
a[i + offset] = (l + r) % MOD
a[i + offset + p] = (l - r) % MOD
rot *= rate2[(~s & -~s).bit_length()]
rot %= MOD
le += 1
else:
p = 1 << (h - le - 2)
rot = 1
for s in range(1 << le):
rot2 = rot * rot % MOD
rot3 = rot2 * rot % MOD
offset = s << (h - le)
for i in range(p):
a0 = a[i + offset]
a1 = a[i + offset + p] * rot
a2 = a[i + offset + p * 2] * rot2
a3 = a[i + offset + p * 3] * rot3
a1na3imag = (a1 - a3) % MOD * IMAG
a[i + offset] = (a0 + a2 + a1 + a3) % MOD
a[i + offset + p] = (a0 + a2 - a1 - a3) % MOD
a[i + offset + p * 2] = (a0 - a2 + a1na3imag) % MOD
a[i + offset + p * 3] = (a0 - a2 - a1na3imag) % MOD
rot *= rate3[(~s & -~s).bit_length()]
rot %= MOD
le += 2
def butterfly_inv(a):
n = len(a)
h = (n - 1).bit_length()
le = h
while le:
if le == 1:
p = 1 << (h - le)
irot = 1
for s in range(1 << (le - 1)):
offset = s << (h - le + 1)
for i in range(p):
l = a[i + offset]
r = a[i + offset + p]
a[i + offset] = (l + r) % MOD
a[i + offset + p] = (l - r) * irot % MOD
irot *= irate2[(~s & -~s).bit_length()]
irot %= MOD
le -= 1
else:
p = 1 << (h - le)
irot = 1
for s in range(1 << (le - 2)):
irot2 = irot * irot % MOD
irot3 = irot2 * irot % MOD
offset = s << (h - le + 2)
for i in range(p):
a0 = a[i + offset]
a1 = a[i + offset + p]
a2 = a[i + offset + p * 2]
a3 = a[i + offset + p * 3]
a2na3iimag = (a2 - a3) * IIMAG % MOD
a[i + offset] = (a0 + a1 + a2 + a3) % MOD
a[i + offset + p] = (a0 - a1 + a2na3iimag) * irot % MOD
a[i + offset + p * 2] = (a0 + a1 - a2 - a3) * irot2 % MOD
a[i + offset + p * 3] = (a0 - a1 - a2na3iimag) * irot3 % MOD
irot *= irate3[(~s & -~s).bit_length()]
irot %= MOD
le -= 2
def multiply(s, t):
n = len(s)
m = len(t)
if min(n, m) <= 60:
a = [0] * (n + m - 1)
for i in range(n):
if i % 8 == 0:
for j in range(m):
a[i + j] += s[i] * t[j]
a[i + j] %= MOD
else:
for j in range(m):
a[i + j] += s[i] * t[j]
return [x % MOD for x in a]
a = s.copy()
b = t.copy()
z = 1 << (n + m - 2).bit_length()
a += [0] * (z - n)
b += [0] * (z - m)
butterfly(a)
butterfly(b)
for i in range(z):
a[i] *= b[i]
a[i] %= MOD
butterfly_inv(a)
a = a[:n + m - 1]
iz = pow(z, MOD - 2, MOD)
return [v * iz % MOD for v in a]
import atexit
import os
import sys
import __pypy__
class Fastio:
def __init__(self):
self.ibuf = bytes()
self.pil = 0
self.pir = 0
self.sb = __pypy__.builders.StringBuilder()
def load(self):
self.ibuf = self.ibuf[self.pil:]
self.ibuf += os.read(0, 131072)
self.pil = 0
self.pir = len(self.ibuf)
def flush(self):
os.write(1, self.sb.build().encode())
def fastin(self):
if self.pir - self.pil < 32:
self.load()
minus = 0
x = 0
while self.ibuf[self.pil] < 45:
self.pil += 1
if self.ibuf[self.pil] == 45:
minus = 1
self.pil += 1
while self.ibuf[self.pil] >= 48:
x = x * 10 + (self.ibuf[self.pil] & 15)
self.pil += 1
if minus:
x = -x
return x
def fastout(self, x):
self.sb.append(str(x))
def fastoutln(self, x):
self.sb.append(str(x))
self.sb.append('\n')
########################### ここまで ###########################
from collections import deque
n, m = map(int, input().split())
a = list(map(int, input().split()))
s = input()
MOD = 998244353
cnt_s = [0] * m
for j in range(m):
if s[j] == 's':
cnt_s[j] = 1
acc_s = [0] * (m + 1)
for j in range(m - 1, -1, -1):
acc_s[j] = acc_s[j + 1] + cnt_s[j]
nums = [[1]]
dnms = [[1, -acc_s[0]-1]]
for j in range(m):
if s[j] == 'a':
nums.append([1, -acc_s[j]])
dnms.append([1, -acc_s[j]-1])
# 分子を分割統治法で求める.
Dnum = len(nums)
d = 1
while (d < Dnum):
for i in range(0, Dnum - d, 2 * d):
nums[i] = multiply(nums[i], nums[i + d])
d <<= 1
# 分母を分割統治法で求める.
Ddnm = len(dnms)
d = 1
while (d < Ddnm):
for i in range(0, Ddnm - d, 2 * d):
dnms[i] = multiply(dnms[i], dnms[i + d])
d <<= 1
# 分母の形式的冪級数としての逆元を求める.
while len(dnms[0]) > n:
dnms[0].pop()
while len(dnms[0]) < n:
dnms[0].append(0)
dnm_inv = [1]
k = 1
while (k < n):
l = min(2 * k, n)
tmp = [0] * l
i_ub = min(l, n)
for i in range(i_ub):
tmp[i] = -dnms[0][i]
tmp = multiply(tmp, dnm_inv)
while len(tmp) > l:
tmp.pop()
tmp[0] += 2
dnm_inv = multiply(tmp, dnm_inv)
while len(dnm_inv) > l:
dnm_inv.pop()
k <<= 1
# g_M(x) を求める.
f = multiply(nums[0], dnm_inv)
# 答えへの寄与を足し合わせる.
res = 0
for i in range(n):
l = i
r = n - 1 - i
res = (res + a[i] * f[l] % MOD * f[r] % MOD) % MOD
print(res)