提出 #44099649

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ソースコード 拡げる

class combi:
    def __init__(self,max_n,mod):
        max_n+=1
        self.mod=mod
        self.fact=[0]*max_n
        self.rev=[0]*max_n
        self.fact_rev=[0]*max_n
        self.fact[0]=1
        self.rev[0]=1
        self.fact_rev[0]=1
        for i in range(max_n):
            if i<=1:
                self.fact[i]=1
                self.rev[i]=1
                self.fact_rev[i]=1
                continue
            self.fact[i]=(i*self.fact[i-1])%mod
            self.rev[i]=mod-((mod//i)*self.rev[mod%i])%mod
            self.fact_rev[i]=(self.fact_rev[i-1]*self.rev[i])%mod
    def combination(self,a,b):
        if a<b:
            return 0
        ans=(self.fact_rev[a-b]*self.fact_rev[b])%self.mod
        return (ans*self.fact[a])%self.mod
N=int(input())
P=list(map(int,input().split()))
R=int(input())
A=list(map(int,input().split()))
MOD=998244353
CO=combi(N,MOD)
dp=[[0 for i in range(N)]for j in range(N)]
for i in range(N):dp[i][0]=1

#make var1 -> var2 table
table=[[0 for i in range(N)]for j in range(N)]
table[0][0]=1
table[1][1]=R
for i in range(1,N-1):
	for j in range(1,i+1):
		table[i+1][j]+=table[i][j]*((R*j)-i)%MOD
		table[i+1][j+1]=table[i][j]*R%MOD
		table[i+1][j]%=MOD

for var in range(N-1,-1,-1):
	#ch4 -> var1
	for i in range(N):
		dp[var][i]=dp[var][i]*CO.fact[i]%MOD

	#var1 -> var2
	tmp=[0]*N
	for i in range(N):
		for j in range(i+1):
			tmp[i]=(tmp[i]+table[i][j]*dp[var][j])%MOD
	tmp,dp[var]=dp[var],tmp

	#var2 ->  var3
	for i in range(N):tmp[i]=0
	val=1
	for i in range(N):
		for j in range(i,N):
			tmp[j]=(tmp[j]+(dp[var][j-i]*val%MOD)*CO.combination(j,i))%MOD
		val=(val*(A[var]-i))%MOD
	tmp,dp[var]=dp[var],tmp

	if var:
		#var3 -> var4
		for i in range(N-1):
			dp[var][i]=(dp[var][i]+dp[var][i+1]*CO.rev[i+1])%MOD
			dp[var][i]=(dp[var][i]*CO.fact_rev[i])%MOD

		#var4 -> pare1
		for i in range(N):tmp[i]=0
		pare=P[var-1]-1
		for i in range(N):
			for j in range(N-i):
				tmp[i+j]=(tmp[i+j]+dp[var][i]*dp[pare][j])%MOD
		dp[pare],tmp=tmp,dp[pare]

	else:
		print(dp[0][0])

提出情報

ジャッジ結果