結果
| 問題 |
No.1762 🐙🐄🌲
|
| コンテスト | |
| ユーザー |
 PCTprobability
|
| 提出日時 | 2021-10-16 19:27:31 |
| 言語 | PyPy3 (7.3.15) |
| 結果 |
AC
|
| 実行時間 | 2,000 ms / 4,000 ms |
| コード長 | 13,239 bytes |
| コンパイル時間 | 544 ms |
| コンパイル使用メモリ | 82,456 KB |
| 実行使用メモリ | 143,840 KB |
| 最終ジャッジ日時 | 2025-01-03 13:05:58 |
| 合計ジャッジ時間 | 37,925 ms |
|
ジャッジサーバーID （参考情報） |
judge1 / judge4 |
（要ログイン）
| ファイルパターン | 結果 |
|---|---|
| sample | AC * 3 |
| other | AC * 47 |
ソースコード
class FPS:
sum_e=(911660635, 509520358, 369330050, 332049552, 983190778, 123842337, 238493703, 975955924, 603855026, 856644456, 131300601, 842657263, 730768835, 942482514, 806263778, 151565301, 510815449, 503497456, 743006876, 741047443, 56250497)
sum_ie=(86583718, 372528824, 373294451, 645684063, 112220581, 692852209, 155456985, 797128860, 90816748, 860285882, 927414960, 354738543, 109331171, 293255632, 535113200, 308540755, 121186627, 608385704, 438932459, 359477183, 824071951)
mod=998244353
Func=[0]
def __init__(self,L):
self.Func=[x%self.mod for x in L]
def butterfly(self,a):
n=len(a)
h=(n-1).bit_length()
for ph in range(1,h+1):
w=1<<(ph-1)
p=1<<(h-ph)
now=1
for s in range(w):
offset=s<<(h-ph+1)
for i in range(p):
l=a[i+offset]
r=a[i+offset+p]*now
r%=self.mod
a[i+offset]=l+r
a[i+offset]%=self.mod
a[i+offset+p]=l-r
a[i+offset+p]%=self.mod
now*=self.sum_e[(~s & -~s).bit_length()-1]
now%=self.mod
return a
def butterfly_inv(self,a):
n=len(a)
h=(n-1).bit_length()
for ph in range(h,0,-1):
w=1<<(ph-1)
p=1<<(h-ph)
inow=1
for s in range(w):
offset=s<<(h-ph+1)
for i in range(p):
l=a[i+offset]
r=a[i+offset+p]
a[i+offset]=l+r
a[i+offset]%=self.mod
a[i+offset+p]=(l-r)*inow
a[i+offset+p]%=self.mod
inow*=self.sum_ie[(~s & -~s).bit_length()-1]
inow%=self.mod
return a
def __mul__(self,other):
if type(other)==int:
ret=[(x*other)%self.mod for x in self.Func]
return FPS(ret)
a=self.Func
b=other.Func
n=len(a);m=len(b)
if not(a) or not(b):
return FPS([])
if min(n,m)<=40:
if n<m:
n,m=m,n
a,b=b,a
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 FPS(res)
z=1<<((n+m-2).bit_length())
a=a+[0]*(z-n)
b=b+[0]*(z-m)
a=self.butterfly(a)
b=self.butterfly(b)
c=[0]*z
for i in range(z):
c[i]=(a[i]*b[i])%self.mod
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 FPS(c[:n+m-1])
def __imul__(self,other):
self=self*other
return self
def __add__(self,other):
res=[0 for i in range(max(len(self.Func),len(other.Func)))]
for i,x in enumerate(self.Func):
res[i]+=x
res[i]%=self.mod
for i,x in enumerate(other.Func):
res[i]+=x
res[i]%=self.mod
return FPS(res)
def __iadd__(self,other):
self=(self+other)
return self
def __sub__(self,other):
res=[0 for i in range(max(len(self.Func),len(other.Func)))]
for i,x in enumerate(self.Func):
res[i]+=x
res[i]%=self.mod
for i,x in enumerate(other.Func):
res[i]-=x
res[i]%=self.mod
return FPS(res)
def __isub__(self,other):
self=self-other
return self
def inv(self,d=-1):
n=len(self.Func)
assert n!=0 and self.Func[0]!=0
if d==-1:d=n
assert d>0
res=[pow(self.Func[0],self.mod-2,self.mod)]
while(len(res)<d):
m=len(res)
f=[self.Func[i] for i in range(min(n,2*m))]
r=res[:]
if len(f)<2*m:
f+=[0]*(2*m-len(f))
elif len(f)>2*m:
f=f[:2*m]
if len(r)<2*m:
r+=[0]*(2*m-len(r))
elif len(r)>2*m:
r=r[:2*m]
f=self.butterfly(f)
r=self.butterfly(r)
for i in range(2*m):
f[i]*=r[i]
f[i]%=self.mod
f=self.butterfly_inv(f)
f=f[m:]
if len(f)<2*m:
f+=[0]*(2*m-len(f))
elif len(f)>2*m:
f=f[:2*m]
f=self.butterfly(f)
for i in range(2*m):
f[i]*=r[i]
f[i]%=self.mod
f=self.butterfly_inv(f)
iz=pow(2*m,self.mod-2,self.mod)
iz*=-iz
iz%=self.mod
for i in range(m):
f[i]*=iz
f[i]%=self.mod
res+=f[:m]
return FPS(res[:d])
def __truediv__(self,other):
if type(other)==int:
invother=pow(other,self.mod-2,self.mod)
ret=[(x*invother)%self.mod for x in self.Func]
return FPS(ret)
assert (other.Func[0]!=0)
return self*(other.inv())
def __itruediv__(self,other):
self=self/other
return self
def __lshift__(self,d):
n=len(self.Func)
self.Func=[0]*d+self.Func
return FPS(self.Func[:n])
def __ilshift__(self,d):
self=self<<d
return self
def __rshift__(self,d):
n=len(self.Func)
self.Func=self.Func[min(n,d):]
self.Func+=[0]*(n-len(self.Func))
return FPS(self.Func)
def __irshift__(self,d):
self=self>>d
return self
def __str__(self):
return f'FPS({self.Func})'
def diff(self):
n=len(self.Func)
ret=[0 for i in range(max(0,n-1))]
for i in range(1,n):
ret[i-1]=(self.Func[i]*i)%self.mod
return FPS(ret)
def integral(self):
n=len(self.Func)
ret=[0 for i in range(n+1)]
for i in range(n):
ret[i+1]=self.Func[i]*pow(i+1,self.mod-2,self.mod)%self.mod
return FPS(ret)
def log(self,deg=-1):
assert self.Func[0]==1
n=len(self.Func)
if deg==-1:deg=n
return (self.diff()*self.inv()).integral()
def mod_sqrt(self,a):
p=self.mod
assert 0<=a and a<p
if a<2:return a
if pow(a,(p-1)//2,p)!=1:return -1
b=1;one=1
while(pow(b,(p-1)>>1,p)==1):
b+=one
m=p-1;e=0
while(m%2==0):
m>>=1
e+=1
x=pow(a,(m-1)>>1,p)
y=(a*x*x)%p
x*=a;
x%=p
z=pow(b,m,p)
while(y!=1):
j=0
t=y
while(t!=one):
j+=1
t*=t
t%=p
z=pow(z,1<<(e-j-1),p)
x*=z
x%=p
z*=z
z%=p
y*=z
y%=p
e=j
return x
def sqrt(self,deg=-1):
n=len(self.Func)
if deg==-1:deg=n
if n==0:return FPS([0 for i in range(deg)])
if self.Func[0]==0:
for i in range(1,n):
if self.Func[i]!=0:
if i&1:return FPS([])
if deg-i//2<=0:break
ret=(self>>i).sqrt(deg-i//2)
if len(ret.Func)==0:return FPS([])
ret=ret<<(i//2)
if len(ret.Func)<deg:
ret.Func+=[0]*(deg-len(ret.Func))
return ret
return FPS([0]*deg)
sqr=self.mod_sqrt(self.Func[0])
if sqr==-1:return FPS([])
assert sqr*sqr%self.mod==self.Func[0]
ret=FPS([sqr])
inv2=(self.mod+1)//2
i=1
while(i<deg):
ret=(ret+FPS(self.Func[:i<<1])*ret.inv(i<<1))*inv2
i<<=1
return FPS(ret.Func[:deg])
def resize(self,deg):
if len(self.Func)<deg:
return FPS(self.Func+[0]*(deg-len(self.Func)))
elif len(self.Func)>deg:
return FPS(self.Func[:deg])
else:
return self
def exp(self,deg=-1):
n=len(self.Func)
assert n>0 and self.Func[0]==0
if deg==-1:deg=n
assert deg>=0
g=[1]
g_fft=[1,1]
self.Func[0]=1
self.resize(deg)
h_drv=self.diff()
m=2
while(m<deg):
f_fft=self.Func[:m]+[0]*m
self.butterfly(f_fft)
#step 2.a
_g=[f_fft[i]*g_fft[i]%self.mod for i in range(m)]
self.butterfly_inv(_g)
_g=_g[m//2:m]+[0]*(m//2)
self.butterfly(_g)
for i in range(m):
_g[i]*=g_fft[i]
_g[i]%=self.mod
self.butterfly_inv(_g)
tmp=pow(-m*m,self.mod-2,self.mod)
for i in range(m):
_g[i]*=tmp
_g[i]%=self.mod
g+=_g[:m//2]
#step 2.b--2.d
t=FPS(self.Func[:m]).diff()
r=h_drv.Func[:m-1]+[0]
self.butterfly(r)
for i in range(m):
r[i]*=f_fft[i]
r[i]%=self.mod
self.butterfly_inv(r)
tmp=pow(-m,self.mod-2,self.mod)
for i in range(m):
r[i]*=tmp
r[i]%=self.mod
t=(t+FPS(r)).Func
t=[t[-1]]+t
t.pop()
#step 2.e
if (2*m<deg):
if len(t)<2*m:
t+=[0]*(2*m-len(t))
elif len(t)>2*m:
t=t[:2*m]
self.butterfly(t)
g_fft=g[:]
if len(g_fft)<2*m:
g_fft+=[0]*(2*m-len(g_fft))
elif len(g_fft)>2*m:
g_fft=g_fft[:2*m]
self.butterfly(g_fft)
for i in range(2*m):
t[i]*=g_fft[i]
t[i]%=self.mod
self.butterfly_inv(t)
tmp=pow(2*m,self.mod-2,self.mod)
t=t[:m]
for i in range(m):
t[i]*=tmp
t[i]%=self.mod
else:
g1=g[m//2:]
s1=t[m//2:]
t=t[:m//2]
g1+=[0]*(m-len(g1))
s1+=[0]*(m-len(s1))
t+=[0]*(m-len(t))
self.butterfly(g1)
self.butterfly(t)
self.butterfly(s1)
for i in range(m):
s1[i]=(g_fft[i]*s1[i]+g1[i]*t[i])%self.mod
for i in range(m):
t[i]*=g_fft[i]
t[i]%=self.mod
self.butterfly_inv(t)
self.butterfly_inv(s1)
for i in range(m//2):
t[i+m//2]+=s1[i]
t[i+m//2]%=self.mod
tmp=pow(m,self.mod-2,self.mod)
for i in range(m):
t[i]*=tmp
t[i]%=self.mod
#step 2.f
v=self.Func[m:min(deg,2*m)]+[0]*(2*m-min(deg,2*m))
t=[0]*(m-1)+t
t=FPS(t).integral().Func
for i in range(m):
v[i]-=t[m+i]
v[i]%=self.mod
#step 2.g
if len(v)<2*m:
v+=[0]*(2*m-len(v))
else:
v=v[:2*m]
self.butterfly(v)
for i in range(2*m):
v[i]*=f_fft[i]
v[i]%=self.mod
self.butterfly_inv(v)
v=v[:m]
tmp=pow(2*m,self.mod-2,self.mod)
for i in range(m):
v[i]*=tmp
v[i]%=self.mod
#step 2.h
for i in range(min(deg-m,m)):
self.Func[m+i]=v[i]
m*=2
return self
def powfps(self,k,deg=-1):
a=self.Func[:]
n=len(self.Func)
l=0
while(l<len(a) and not a[l]):
l+=1
if l*k>=n:
return FPS([0]*n)
ic=pow(a[l],self.mod-2,self.mod)
pc=pow(a[l],k,self.mod)
a=FPS([(a[i]*ic)%self.mod for i in range(l,len(a))]).log()
a*=k
a=a.exp()
a*=pc
a=[0]*(l*k)+a.Func[:n-l*k]
return FPS(a)
def modpow(a,b,m):
res=1
while b:
if b%2:
res*=a
res%=m
a*=a
a%=m
b//=2
return res
def binom(a,b):
res=1
for i in range(a-b+1,a+1):
res*=i
res%=998244353
for i in range(1,b+1):
res*=modpow(i,998244351,998244353)
res%=998244353
return res
n,p=map(int,input().split())
mod=998244353
if n%4!=1:
print(0)
exit()
m=n//4
if m-1<p*7:
print(0)
exit()
ans=1
for i in range(1,n+1):
ans*=i
ans%=mod
for i in range(1,m+1):
ans*=modpow(i,mod-2,mod)
ans%=mod
ans*=modpow(modpow(6,m,mod),mod-2,mod)
ans*=modpow(n-m,mod-2,mod)
ans%=mod
x=[0 for i in range(m)]
y=1
for i in range(min(7,m)):
x[i]=y
y*=modpow(i+1,mod-2,mod)
y%=mod
f=FPS(x)
f=f.powfps(3*m+1-p)
z=1
for i in range(1,8):
z*=modpow(i,mod-2,mod)
z%=mod
ans*=f.Func[m-1-p*7]
ans*=modpow(z,p,mod)
ans%=mod
for i in range(1,m):
ans*=i
ans%=mod
ans*=binom(3*m+1,p)
ans%=mod
print(ans)