Problem p02723 (python)

Fixed submission:
import sys


def input() -> str:
    return sys.stdin.readline().rstrip("\r\n")


def main():
    s = input()
    if len(s) == 6 and s[-2] == s[-1] and s[2] == s[3]:
        print('Yes')
    else:
        print('No')

if __name__ == "__main__":

    main()

Buggy submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
import sys

MAX_INT = 2**62-1
sys.setrecursionlimit(10**6)

input = sys.stdin.readline


def solve(g, f, fi, m):
    def dfs(pre, cur, memo, m):
        if (pre, cur) in memo:
            return memo[pre, cur]

        num, ways = 1, 1

        for nxt in g[cur]:
            if nxt == pre:
                continue
            n, w = dfs(cur, nxt, memo, m)
            num += n
            ways = ways * w % m * fi[n] % m

        ways = ways * f[num-1] % m
        memo[pre, cur] = num, ways
        return num, ways

    memo = {}
    print(*[dfs(None, i, memo, m)[1] for i in range(1, len(g))], sep='\n')


def main():
    n = int(input())
    g = [[] for _ in range(n+1)]
    mod = 10**9 + 7

    fact = [1] * (n+1)
    fact_inv = [1] * (n+1)

    for i in range(1, n+1):
        fact[i] = fact[i-1] * i % mod

    fact_inv[-1] = pow(fact[-1], mod-2, mod)

    for i in range(1, n)[::-1]:
        fact_inv[i] = fact_inv[i+1] * (i+1) % mod

    for _ in range(n-1):
        a, b = map(int, input().split())
        g[a].append(b)
        g[b].append(a)

    solve(g, fact, fact_inv, mod)


if __name__ == "__main__":

    main()

Buggy submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
import sys
from collections import defaultdict


MAX_INT = 2**62-1
sys.setrecursionlimit(10**6)

input = sys.stdin.readline


N = 2 * (10**5) + 1
MOD = 10**9 + 7

fact = [1] * N
fact_inv = [0] * N

for i in range(1, 2 * (10**5)+1):
    fact[i] = fact[i-1] * i % MOD
    fact_inv[i] = pow(fact[i], MOD-2, MOD)


def solve(g):
    def dfs(pre, cur):
        if pre in memo and cur in memo[pre]:
            return memo[pre][cur]

        num, ways = 1, 1

        for nxt in g[cur]:
            if nxt == pre:
                continue
            n, w = dfs(cur, nxt)
            num += n
            ways = ways * w % m * fi[n] % m

        ways = ways * f[num-1] % m
        memo[pre][cur] = num, ways
        return num, ways

    m = MOD
    memo = defaultdict(dict)
    f, fi = fact, fact_inv

    for i in range(1, len(g)):
        print(dfs(None, i)[1])


def main():
    n = int(input())
    g = [[] for _ in range(n+1)]

    for _ in range(n-1):
        a, b = map(int, input().split())
        g[a].append(b)
        g[b].append(a)

    solve(g)


if __name__ == "__main__":

    main()

Buggy submission (verdict: Runtime Error):
# -*- coding: utf-8 -*-
import sys
from collections import defaultdict


MAX_INT = 2**62-1
sys.setrecursionlimit(10**6)

input = sys.stdin.readline


N = 2 * (10**5) + 1
MOD = 10**9 + 7

fact = [1] * N
fact_inv = [0] * N

for i in range(1, 2 * (10**5)+1):
    fact[i] = fact[i-1] * i % MOD
    fact_inv[i] = pow(fact[i], MOD-2, MOD)


def solve(g):
    def dfs(pre, cur):
        if pre in memo and cur in memo[pre]:
            return memo[pre][cur]

        num, ways = 1, 1

        for nxt in g[cur]:
            if nxt == pre:
                continue
            n, w = dfs(cur, nxt)
            num += n
            ways = ways * w % m * fi[n] % m

        ways = ways * f[num-1] % m
        memo[pre][cur] = num, ways
        return num, ways

    m = MOD
    memo = defaultdict(dict)
    f, fi = fact, fact_inv

    for i in range(1, len(g)):
        print(dfs(None, i)[1])


def main():
    n = int(input())
    g = [[] for _ in range(n+1)]

    for _ in range(n-1):
        a, b = map(int, input().split())
        g[a].append(b)
        g[b].append(a)

    solve(g)


if __name__ == "__main__":

    main()