import sys input = lambda :sys.stdin.readline().rstrip() mi = lambda :map(int,input().split()) li = lambda :list(mi()) mod = 998244353 omega = pow(3,119,mod) rev_omega = pow(omega,mod-2,mod) N = 2*10**5 g1 = [1]*(N+1) # 元テーブル g2 = [1]*(N+1) #逆元テーブル inv = [1]*(N+1) #逆元テーブル計算用テーブル for i in range( 2, N + 1 ): g1[i]=( ( g1[i-1] * i ) % mod ) inv[i]=( ( -inv[mod % i] * (mod//i) ) % mod ) g2[i]=( (g2[i-1] * inv[i]) % mod ) inv[0]=0 def _ntt(f,L,reverse=False): F=[f[i] for i in range(L)] n = L.bit_length() - 1 base = omega if reverse: base = rev_omega if not n: return F size = 2**n wj = pow(base,2**22,mod) res = [0]*2**n for i in range(n,0,-1): use_omega = pow(base,2**(22+i-n),mod) res = [0]*2**n size //= 2 w = 1 for j in range(0,L//2,size): for a in range(size): res[a+j] = (F[a+2*j] + w * F[a+size+2*j]) % mod t = (w * wj) % mod res[L//2+a+j] = (F[a+2*j] + t * F[a+size+2*j]) % mod w = (w * use_omega) % mod F = res return res def ntt(f,L=0): l = len(f) if not L: L = 1<<((l-1).bit_length()) while len(f) c[i] = sum(a[j] * b[i - j] for j in range(i + 1)) % 998244353. It returns an empty list if at least one of a and b are empty. Constraints ----------- > len(a) + len(b) <= 8388609 Complexity ---------- > O(n log n), where n = len(a) + len(b). """ n = len(a) m = len(b) if n == 0 or m == 0: return [] if min(n, m) <= 0: return _convolution_naive(a, b) if a is b: return _convolution_square(a) return _convolution_fft(a, b) def bostan_mori(P,_Q,N): Q = [a for a in _Q] """ [x^N]P(x)/Q(x)を求める """ d = len(Q) - 1 z = 1 << (2*d).bit_length() iz = pow(z, _fft_mod - 2, _fft_mod) while N: """ P(x)/Q(x) = P(x)Q(-x)/Q(x)Q(-x) """ P += [0] * (z-len(P)) Q += [0] * (z-len(Q)) _butterfly(P) _butterfly(Q) dft_t = Q.copy() for i in range(0,z,2): dft_t[i],dft_t[i^1] = dft_t[i^1],dft_t[i] P = [a*b % mod for a,b in zip(P,dft_t)] _butterfly_inv(P) Q = [a*b % mod for a,b in zip(Q,dft_t)] _butterfly_inv(Q) P = [a * iz % mod for a in P][N&1::2] Q = [a * iz % mod for a in Q][0::2] N >>= 1 res = P[0] * pow(Q[0],mod-2,mod) % mod return res from collections import deque N = int(input()) + 1 parent = [-1] + li() W = [-1] + li() edge = [[] for v in range(N)] for v in range(1,N): edge[parent[v]].append(v) dep = [0] * N prop = [1] * N deq = deque([0]) while deq: v = deq.popleft() S = sum(W[nv] for nv in edge[v]) iS = pow(S,mod-2,mod) for nv in edge[v]: dep[nv] = dep[v] + 1 prop[nv] = prop[v] * iS * W[nv] % mod deq.append(nv) f = [0] * (N+4) f[0] = 1 for v in range(N): if not edge[v]: f[dep[v]+1] -= prop[v] f[dep[v]+1] %= mod for i in range(1,N+4)[::-1]: f[i] -= f[i-1] f[i] %= mod ans = [] for _ in range(int(input())): A,K = mi() if dep[A] > K: ans.append(0) continue K -= dep[A] res = bostan_mori([1],f,K) * prop[A] % mod if A == 0: res -= 1 res %= mod ans.append(res) print(*ans,sep="\n")