結果
| 問題 | No.2485 Add to Variables (Another) |
| コンテスト | |
| ユーザー |
 detteiuu
|
| 提出日時 | 2026-09-05 17:37:57 |
| 言語 | PyPy3 (7.3.23 + ACL) |
| 結果 |
AC
不安定
|
| 実行時間 | 1,058 ms / 2,000 ms |
| + 806µs | |
| コード長 | 7,513 bytes |
| 記録 | |
| コンパイル時間 | 232 ms |
| コンパイル使用メモリ | 96,208 KB |
| 実行使用メモリ | 282,612 KB |
| 最終ジャッジ日時 | 2026-09-05 17:38:22 |
| 合計ジャッジ時間 | 18,809 ms |
|
ジャッジサーバーID （参考情報） |
judge5_0 / judge1_0 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 5 |
| other | AC * 39 |
ソースコード
class FFT():
def primitive_root_constexpr(self,m):
if m==2:return 1
if m==167772161:return 3
if m==469762049:return 3
if m==754974721:return 11
if m==998244353:return 3
divs=[0]*20
divs[0]=2
cnt=1
x=(m-1)//2
while(x%2==0):x//=2
i=3
while(i*i<=x):
if (x%i==0):
divs[cnt]=i
cnt+=1
while(x%i==0):
x//=i
i+=2
if x>1:
divs[cnt]=x
cnt+=1
g=2
while(1):
ok=True
for i in range(cnt):
if pow(g,(m-1)//divs[i],m)==1:
ok=False
break
if ok:
return g
g+=1
def bsf(self,x):
res=0
while(x%2==0):
res+=1
x//=2
return res
rank2=0
root=[]
iroot=[]
rate2=[]
irate2=[]
rate3=[]
irate3=[]
def __init__(self,MOD):
self.mod=MOD
self.g=self.primitive_root_constexpr(self.mod)
self.rank2=self.bsf(self.mod-1)
self.root=[0 for i in range(self.rank2+1)]
self.iroot=[0 for i in range(self.rank2+1)]
self.rate2=[0 for i in range(self.rank2)]
self.irate2=[0 for i in range(self.rank2)]
self.rate3=[0 for i in range(self.rank2-1)]
self.irate3=[0 for i in range(self.rank2-1)]
self.root[self.rank2]=pow(self.g,(self.mod-1)>>self.rank2,self.mod)
self.iroot[self.rank2]=pow(self.root[self.rank2],self.mod-2,self.mod)
for i in range(self.rank2-1,-1,-1):
self.root[i]=(self.root[i+1]**2)%self.mod
self.iroot[i]=(self.iroot[i+1]**2)%self.mod
prod=1;iprod=1
for i in range(self.rank2-1):
self.rate2[i]=(self.root[i+2]*prod)%self.mod
self.irate2[i]=(self.iroot[i+2]*iprod)%self.mod
prod=(prod*self.iroot[i+2])%self.mod
iprod=(iprod*self.root[i+2])%self.mod
prod=1;iprod=1
for i in range(self.rank2-2):
self.rate3[i]=(self.root[i+3]*prod)%self.mod
self.irate3[i]=(self.iroot[i+3]*iprod)%self.mod
prod=(prod*self.iroot[i+3])%self.mod
iprod=(iprod*self.root[i+3])%self.mod
def butterfly(self,a):
n=len(a)
h=(n-1).bit_length()
LEN=0
while(LEN<h):
if (h-LEN==1):
p=1<<(h-LEN-1)
rot=1
for s in range(1<<LEN):
offset=s<<(h-LEN)
for i in range(p):
l=a[i+offset]
r=a[i+offset+p]*rot
a[i+offset]=(l+r)%self.mod
a[i+offset+p]=(l-r)%self.mod
rot*=self.rate2[(~s & -~s).bit_length()-1]
rot%=self.mod
LEN+=1
else:
p=1<<(h-LEN-2)
rot=1
imag=self.root[2]
for s in range(1<<LEN):
rot2=(rot*rot)%self.mod
rot3=(rot2*rot)%self.mod
offset=s<<(h-LEN)
for i in range(p):
a0=a[i+offset]
a1=a[i+offset+p]*rot
a2=a[i+offset+2*p]*rot2
a3=a[i+offset+3*p]*rot3
a1na3imag=(a1-a3)%self.mod*imag
a[i+offset]=(a0+a2+a1+a3)%self.mod
a[i+offset+p]=(a0+a2-a1-a3)%self.mod
a[i+offset+2*p]=(a0-a2+a1na3imag)%self.mod
a[i+offset+3*p]=(a0-a2-a1na3imag)%self.mod
rot*=self.rate3[(~s & -~s).bit_length()-1]
rot%=self.mod
LEN+=2
def butterfly_inv(self,a):
n=len(a)
h=(n-1).bit_length()
LEN=h
while(LEN):
if (LEN==1):
p=1<<(h-LEN)
irot=1
for s in range(1<<(LEN-1)):
offset=s<<(h-LEN+1)
for i in range(p):
l=a[i+offset]
r=a[i+offset+p]
a[i+offset]=(l+r)%self.mod
a[i+offset+p]=(l-r)*irot%self.mod
irot*=self.irate2[(~s & -~s).bit_length()-1]
irot%=self.mod
LEN-=1
else:
p=1<<(h-LEN)
irot=1
iimag=self.iroot[2]
for s in range(1<<(LEN-2)):
irot2=(irot*irot)%self.mod
irot3=(irot*irot2)%self.mod
offset=s<<(h-LEN+2)
for i in range(p):
a0=a[i+offset]
a1=a[i+offset+p]
a2=a[i+offset+2*p]
a3=a[i+offset+3*p]
a2na3iimag=(a2-a3)*iimag%self.mod
a[i+offset]=(a0+a1+a2+a3)%self.mod
a[i+offset+p]=(a0-a1+a2na3iimag)*irot%self.mod
a[i+offset+2*p]=(a0+a1-a2-a3)*irot2%self.mod
a[i+offset+3*p]=(a0-a1-a2na3iimag)*irot3%self.mod
irot*=self.irate3[(~s & -~s).bit_length()-1]
irot%=self.mod
LEN-=2
def convolution(self,a,b):
n=len(a);m=len(b)
if not(a) or not(b):
return []
if min(n,m)<=40:
res=[0]*(n+m-1)
for i in range(n):
for j in range(m):
res[i+j]+=a[i]*b[j]
res[i+j]%=self.mod
return res
z=1<<((n+m-2).bit_length())
a=a+[0]*(z-n)
b=b+[0]*(z-m)
self.butterfly(a)
self.butterfly(b)
c=[(a[i]*b[i])%self.mod for i in range(z)]
self.butterfly_inv(c)
iz=pow(z,self.mod-2,self.mod)
for i in range(n+m-1):
c[i]=(c[i]*iz)%self.mod
return c[:n+m-1]
MOD = 998244353
def factorial(n):
F = [1]
for i in range(1, n+1):
F.append(F[-1]*i%MOD)
invF = [pow(F[-1], -1, MOD)]
for i in reversed(range(n)):
invF.append(invF[-1]*(i+1)%MOD)
invF = invF[::-1]
return F, invF
F, invF = factorial(10**6*3)
N, M = map(int, input().split())
B = list(map(int, input().split()))
if N == 1:
exit(print(F[M]*invF[B[0]]%MOD*invF[M-B[0]]%MOD))
B0, BN = B[0], B[-1]
DM = M
C = [B[0]]
for i in range(N-1):
C.append(B[i+1]-B[i])
C.append(-B[-1])
cnt0, cntN = 0, 0
for i in range(1, N):
if 0 < C[i]:
cntN += C[i]
elif C[i] < 0:
cnt0 += -C[i]
M -= cnt0+cntN
if M < 0:
exit(print(0))
for i in range(N+1):
C[i] = abs(C[i])
allC = -1
if B0 < cnt0 or BN < cntN or (B0-cnt0) != (BN-cntN):
exit(print(0))
allC = B0-cnt0
G = []
for i in range(1, N):
H = []
for j in range(M+1):
H.append(invF[C[i]+j]*invF[j]%MOD)
G.append(H)
fft = FFT(MOD)
while 2 <= len(G):
NG = []
for i in range(len(G)//2):
NG.append(fft.convolution(G[i*2], G[i*2+1]))
if len(G)%2 == 1:
NG.append(G[-1])
G = NG
ansF = G[0]
ans = 0
for i in range(len(ansF)):
if i*2 <= M and i <= allC:
rem = allC-i
rem2 = M-i*2-rem
if rem2 < 0: continue
ans += ansF[i]*invF[rem]%MOD*invF[rem2]%MOD*F[DM]%MOD
ans %= MOD
print(ans)