alexjercan/bugnet huggingface dataset:
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import deque

n = int(input())
a = list(map(int, input().split()))
b = deque()
for i in range(n):
    if i % 2 == 0:
        b.append(a[i])
    else:
        b.appendleft(a[i])

if n % 2 != 0:
    for i in reversed(b):
        print(i, end=" ")
else:
    for i in b:
        print(i, end=" ")


Error: TLE

Fixed submission:

n = int(input())
a = list(map(int, input().split()))
b = []
for i in range(n):
    if i % 2 == 0:
        b.append(a[i])
    else:
        b.insert(0, a[i])

if n % 2 != 0:
    b.reverse()
for i in b:
    print(i, end=" ")
Problem p03673 (Python) — buggy submission, verdict: Runtime Error

# -*- coding: utf-8 -*-
N = int(input())
a = input().split()

if N % 2 == 0:
    b = a[N::-2] + a[::2]
else:
    b = a[N::-2] + a[1::2]

print(" ".join(b))


Error: TypeError: sequence item 0: expected str instance, int found
Traceback (most recent call last):
  File "/home/alex/Documents/bug-detection/input/Project_CodeNet/data/p03673/Python/s153812591.py", line 6, in <module>
    print(" ".join(a[N::-2] + a[::2]))
TypeError: sequence item 0: expected str instance, int found


Fixed submission:

# -*- coding: utf-8 -*-
N = int(input())
a = list(map(int, input().split()))

if N % 2 == 0:
    print(" ".join(a[N::-2] + a[::2]))
else:
    print(" ".join(a[N::-2] + a[1::2]))
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import deque

n = int(input())
a = list(map(int, input().split()))
b = deque()

for i in range(n):
    if i % 2 == 0:
        b.append(a[i])
    else:
        b.appendleft(a[i])

if n % 2 == 1:
    b.reverse()

print(*b)


Error: TLE

Fixed submission:

n = int(input())
a = list(map(int, input().split()))
b = []

for i in range(n):
    b.append(a[i])
    b.reverse()

print(*b)
Problem p03673 (Python) — buggy submission, verdict: Runtime Error

n = int(input())
a = list(map(int, input().split()))
a1 = []
a2 = []
for i in range(n):
    if i % 2 == 0:
        a1.append(a[i])
    else:
        a2.append(a[i])
if n % 2 == 0:
    a2.reverse()
    print(*a2 + a1)
else:
    a1.reverse()
    print(*a1 + a2)


Error: 0

Fixed submission:

n = int(input())
a = list(map(int, input().split()))
a1 = []
a2 = []
for i in range(n):
    if i % 2 == 0:
        a1.append(a[i])
    else:
        a2.append(a[i])
if n % 2 == 0:
    rev = list(reversed(a2))
    print(*rev, *a1)
else:
    rev = list(reversed(a1))
    print(*rev, *a2)
Problem p03673 (Python) — buggy submission, verdict: Runtime Error

n = int(input())
a = list(map(int, input().split()))
even = []
odd = []
for i in range(n):
    if i % 2:
        even.append(a[i])
    else:
        odd.append(a[i])
if n % 2 == 0:
    print(*even[::-1], end=" ")
    print(*odd)
else:
    print(*odd[::-1], end=" ")
    print(*even)


Error: 0

Fixed submission:

n = int(input())
a = list(map(int, input().split()))
even = []
odd = []
for i in range(n):
    if i % 2:
        even.append(a[i])
    else:
        odd.append(a[i])
if n % 2 == 0:
    print(*even[::-1], *odd)
else:
    print(*odd[::-1], *even)
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import deque

n = int(input())
a = list(map(int, input().split()))

b = deque()


for i in range(n):
    if i % 2 == 0:
        b.appendleft(a[i])
    else:
        b.append(a[i])
if n % 2 == 0:
    b = list(b)[::-1]
print(*b)


Error: TLE

Fixed submission:

n = int(input())
a = list(map(int, input().split()))

b = []

for i in range(n):
    b.append(a[i])
    b = b[::-1]
print(*b)
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
a = list(map(int, input().split()))
if n % 2:
    for i in range(n // 2 + 1):
        print(str(a[n - 1 - 2 * i]) + " ", end="")
    for i in range(n // 2):
        print(str(a[1 + 2 * i]) + " ", end="")
    print()
else:
    for i in range(n // 2):
        print(str(a[n - 1 - 2 * i]) + " ", end="")
    for i in range(n // 2):
        print(str(a[2 * i]) + " ", end="")
    print()


Error: TLE

Fixed submission:

n = int(input())
a = list(map(int, input().split()))
b = []
for p in a:
    b.append(p)
    b.reverse()
for p in b:
    print(str(p) + " ", end="")
print()
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = list(map(int, input().split()))

if len(A) == 1:
    print(A[0])
    exit(0)

B_left = []
B_right = []
for i, a in enumerate(A):
    if i % 2 == 0:
        B_right.append(a)
    else:
        B_left.append(a)

if len(A) % 2 == 0:
    B = B_left[::-1] + B_right
else:
    B = B_right[::-1] + B_left
print(*B)


Error: TLE

Fixed submission:

N = int(input())
A = list(map(int, input().split()))

B = []
for i in range(N):
    B.append(A[i])
    B = B[::-1]

print(*B)
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import deque

n = int(input())
A = list(map(int, input().split()))
deq = deque([])

for i in range(1, n + 1):
    if i % 2 == 1:
        deq.append(A[i - 1])
    else:
        deq.appendleft(A[i - 1])

if n % 2 == 0:
    print(*deq)
else:
    print(*reversed(list(deq)))


Error: TLE

Fixed submission:

n = int(input())
A = list(map(int, input().split()))
B = []

for i in range(n):
    B.append(A[i])
    B = B[::-1]

print(*B)
Problem p03673 (Python) — buggy submission, verdict: Runtime Error

from collections import deque

n = int(input())
a = list(map(int, input().split()))

d = deque()
for i in range(n):
    if i % 2 != 0:
        d.append(a[i])
    else:
        d.appendleft(a[i])

if n % 2 == 0:
    print(*list(reversed(d)))
else:
    print(*d)


Error: 0

Fixed submission:

n = int(input())
a = list(map(int, input().split()))

if len(a) % 2 == 0:
    print(*list(reversed(a[1::2])), *a[0::2])
else:
    print(*list(reversed(a[0::2])), *a[1::2])
Problem p03673 (Python) — buggy submission, verdict: Time Limit Exceeded

n = 4
a = [1, 2, 3, 4]

n = int(input())
a = input().split()


if n % 2 == 0:
    y = [a[j] for j in range(1, n, 2)][::-1]
    z = [a[j] for j in range(0, n, 2)]

else:
    y = [a[j] for j in range(0, n, 2)][::-1]
    z = [a[j] for j in range(1, n, 2)]

print(" ".join(map(str, y + z)))


Error: TLE

Fixed submission:

n = int(input())
a = input().split()

b = []

for i in a:
    b.append(i)
    b.reverse()

print(" ".join(b))
Problem p03674 (Python) — buggy submission, verdict: Runtime Error

N = int(input())
A = [int(_) for _ in input().split()]
mod = 10**9 + 7

f = [1] * (N + 2)
fi = [1] * (N + 2)
for i in range(2, N + 2):
    f[i] = i * f[i - 1]
    f[i] %= mod
for i in range(2, N + 2):
    fi[i] = fi[i - 1] * pow(i, mod - 2, mod)
    fi[i] %= mod


def comb(n, r):
    if 0 <= n and 0 <= r and 0 <= n - r:
        return (f[n] * fi[r] * fi[n - r]) % mod
    else:
        return 0


b = set()
for a in A:
    if a in b:
        break
    b.add(a)
c = []
for i in range(N + 1):
    if A[i] == a:
        c += [i]
i, j = c
for x in range(1, N + 2):
    print((comb(N + 1, x) - (comb(N - j + i, x - 1))) % mod)


Error: 0

Fixed submission:

N = int(input())
A = [int(_) for _ in input().split()]
mod = 10**9 + 7

f = [1] * (N + 2)
fi = [1] * (N + 2)
for i in range(2, N + 2):
    f[i] = i * f[i - 1]
    f[i] %= mod
for i in range(2, N + 2):
    fi[i] = fi[i - 1] * pow(i, mod - 2, mod)
    fi[i] %= mod


def comb(n, r):
    if 0 <= n and 0 <= r and 0 <= n - r:
        return (f[n] * fi[r] * fi[n - r]) % mod
    else:
        return 0


b = set()
for a in A:
    if a in b:
        break
    b.add(a)
c = []
for i in range(N):
    if A[i] == a:
        c += [i]
i, j = c
for x in range(1, N + 2):
    print((comb(N + 1, x) - (comb(N - j + i, x - 1))) % mod)
Problem p03675 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import deque

n = int(input())
a = list(map(int, input().split()))

b = deque()

for i in range(n):
    if i % 2 != n % 2:
        b.appendleft(a[i])
    else:
        b.append(a[i])

print(" ".join(map(str, b)))


Error: TLE

Fixed submission:

n = int(input())
a = list(map(int, input().split()))

b = []

for i in range(n):
    if i % 2 != n % 2:
        b.insert(0, a[i])
    else:
        b.append(a[i])

print(" ".join(map(str, b)))
Problem p03675 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = list(map(int, input().split()))

ans = []
if N % 2 == 0:
    l1 = A[0::2]
    l2 = A[1::2]
    l2 = l2[::-1]
    ans = l2 + l1
else:
    l1 = A[0::2]
    l2 = A[1::2]
    l1 = l1[::-1]
    ans = l1 + l2

print(" ".join(list(map(str, ans))))


Error: TLE

Fixed submission:

N = int(input())
A = list(map(int, input().split()))

ans = [A[0]]
for i in range(1, N):
    if i % 2 == 0:
        ans.append(A[i])
    else:
        ans.insert(0, A[i])

if N % 2 == 1:
    ans = ans[::-1]

print(" ".join(list(map(str, ans))))
Problem p03675 (Python) — buggy submission, verdict: Runtime Error

from collections import deque

n = int(input())
a = list(map(int, input().split()))

b = deque([])
rev = 1
for i in a:
    if rev == 1:
        b.append(i)
        rev = -1
    elif rev == -1:
        b.appendleft(i)
        rev = 1

print(*(b if rev == 1 else list(b)[::-1]))


Error: 0

Fixed submission:

from collections import deque

n = int(input())
a = list(map(int, input().split()))

b = deque([])
rev = 1
for i in a:
    if rev == 1:
        b.append(i)
        rev = -1
    elif rev == -1:
        b.appendleft(i)
        rev = 1

print(*(b if rev == 1 else b[::-1]))
Problem p03676 (Python) — buggy submission, verdict: Runtime Error

def ncr(n, r):
    return fact[n] * inv_fact[r] * inv_fact[n - r] % div


def find_duplicated(aa):
    appeared = [-1] * (n + 1)
    for i, a in enumerate(aa):
        if appeared[a] >= 0:
            return appeared[a], i
        appeared[a] = i


div = int(1e9 + 7)
n = int(input())
aa = list(map(int, input().split()))

fact, inv_fact = [1], [1]
fact_tmp = 1
for i in range(1, n + 2):
    fact_tmp *= i
    fact_tmp %= div
    fact.append(fact_tmp)
    inv_fact.append(pow(fact_tmp, div - 2, div))

i1, i2 = find_duplicated(aa)
outside_n = n + 1 - (i2 - i1 + 1)

for part_n in range(1, n + 2):
    sub = ncr(outside_n, part_n - 1) if outside_n >= part_n - 1 else 0
    print((ncr(n + 1, part_n) - sub) % div)


Error: 0

Fixed submission:

import sys

sys.setrecursionlimit(100001)


def get_ncr(div):
    cache = {}

    def f(*args):
        if args in cache:
            return cache[args]
        n, r = args
        if r == 0 or n == r:
            cache[args] = 1
            return 1
        cache[args] = (f(n - 1, r) + f(n - 1, r - 1)) % div
        return cache[args]

    return f


def find_duplicated(aa):
    appeared = [-1] * (n + 1)
    for i, a in enumerate(aa):
        if appeared[a] >= 0:
            return appeared[a], i
        appeared[a] = i


n = int(input())
aa = list(map(int, input().split()))
i1, i2 = find_duplicated(aa)
between_n = i2 - i1 + 1
outside_n = n + 1 - between_n
div = int(1e9 + 7)
ncr = get_ncr(div)

for part_n in range(1, n + 2):
    sub = ncr(outside_n, part_n - 1) if outside_n >= part_n - 1 else 0
    print((ncr(n + 1, part_n) - sub) % div)
Problem p03680 (Python) — buggy submission, verdict: Runtime Error

n = int(input())
buttons = [0]
target_index = 0
for _ in range(n):
    buttons.append(int(input()))

count = 0
prev_index = 1
while count < n:
    if prev_index < 1 or len(buttons) <= prev_index:
        count = -1
        break

    next_index = buttons[prev_index]
    count += 1
    if next_index == 2:
        break
    else:
        prev_index = next_index

print(count if count < n else -1)


Error: WA

Fixed submission:

n = int(input())
buttons = [0]
target_index = 0
for _ in range(n):
    num = int(input())
    buttons.append(num)

count = 0
next_index = 2
while count < n:
    if next_index < 1 or len(buttons) - 1 <= next_index:
        count = -1
        break

    prev_index = buttons.index(next_index)
    count += 1
    if prev_index == 1:
        break
    else:
        next_index = prev_index

print(count if count < n else -1)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = [int(input()) for _ in range(N)]

B = [1]
i = 0
cnt = 0
flag = False
for _ in range(N):
    i = A[i] - 1
    cnt += 1
    if i == 1:
        flag = True
        break

print(cnt) if flag else print(-1)


Error: TLE

Fixed submission:

N = int(input())
A = [int(input()) for _ in range(N)]

B = [1]
i = 0
flag = False
for _ in range(N):
    if 2 in B:
        flag = True
        break
    elif A[i] in B:
        break
    B.append(A[i])
    i = A[i] - 1

print(len(B) - 1) if flag else print(-1)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
a = [0] + [int(input()) for i in range(n)]
c = a[1]
p = 1
while c > 2:
    d = a[c]
    a[c] = 0
    c = d
    p += 1

if c == 2:
    print(p)
else:
    print(-1)


Error: TLE

Fixed submission:

n = int(input())
a = [0] + [int(input()) for i in range(n)]
c = a[1]
p = 1
while c > 2:
    c = a[c]
    p += 1

if c == 2:
    print(p)
else:
    print(-1)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input().strip())
a = [int(input().strip()) for _ in range(n)]
visited = [False] * n
visited[0] = True
now = 0
ans = 0
while True:
    now = a[now] - 1
    ans += 1
    if now == 1:
        print(ans)
        exit()
    elif visited[now]:
        print(-1)
        exit()
    visited[now] = True


Error: TLE

Fixed submission:

n = int(input().strip())
a = [int(input().strip()) for _ in range(n)]
visited = [False] * n
visited[0] = True
now = 0
ans = 0
while True:
    now = a[now] - 1
    ans += 1
    if now == 1:
        print(ans)
        exit()
    elif visited[now]:
        print(-1)
        exit()
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
nlist = [int(input()) for i in range(n)]
c = 0
x = 1
while x != 2 and c < n:
    x = nlist[x - 1]
    c += 1
if x == 2:
    print(c)
else:
    print(-1)


Error: TLE

Fixed submission:

n = int(input())
nlist = [int(input()) for i in range(n)]
xlist = []
c = 0
x = 1
while x != 2 and x not in xlist and c < n:
    xlist.append(x)
    x = nlist[x - 1]
    c += 1
if x == 2:
    print(c)
else:
    print(-1)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

def main():
    n = int(input())
    a = [int(input()) for i in range(n)]

    btn = 1
    hist = set()
    while True:
        if btn == 2:
            print(len(hist))
            break

        if btn in hist:
            print(-1)
            break

        hist.add(btn)
        btn = a[btn - 1]


if __name__ == "__main__":
    main()


Error: TLE

Fixed submission:

def main():
    n = int(input())
    a = [int(input()) for i in range(n)]

    btn = 1
    hist = []
    while True:
        if btn == 2:
            print(len(hist))
            break

        if btn in hist:
            print(-1)
            break

        hist.append(btn)
        btn = a[btn - 1]


if __name__ == "__main__":
    main()
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
a = [int(input()) for _ in range(N)]

i = 1
c = 0
ans = -1
for _ in range(N):
    i = a[i - 1]
    c += 1
    if i == 2:
        ans = c
        break
print(ans)


Error: TLE

Fixed submission:

N = int(input())
a = [int(input()) for _ in range(N)]

i = 1
c = 0
while True:
    i = a[i - 1]
    c += 1
    if i == 1:
        c = -1
        break
    elif i == 2:
        break
print(c)
Problem p03680 (Python) — buggy submission, verdict: Runtime Error

n = int(input())
a = [int(input()) for i in range(n)]
counter = 0
i = 1
while counter <= n:
    i = a[i - 1]
    counter += 1
    if i == 2:
        print(counter)
        break
else:
    print(-1)


Error: TypeError: 'str' object cannot be interpreted as an integer
Traceback (most recent call last):
  File "/home/alex/Documents/bug-detection/input/Project_CodeNet/data/p03680/Python/s197975639.py", line 2, in <module>
    a = (input() for i in range(n))
TypeError: 'str' object cannot be interpreted as an integer


Fixed submission:

n = input()
a = (input() for i in range(n))
counter = 0
i = 1
while counter < n:
    i = a[i - 1]
    counter += 1
    if i == 2:
        print(counter)
        break
else:
    print(-1)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = []
for _ in range(N):
    A.append(int(input()))

pushed = [False] * N
pushed[0] = True
now = 0
cnt = 0

while True:
    next = A[now] - 1

    if pushed[next]:
        cnt = -1
        break

    if next == 1:
        cnt += 1
        break

    if next != 1:
        now = next
        pushed[next] = True
        cnt += 1


print(cnt)


Error: TLE

Fixed submission:

N = int(input())
A = []
for _ in range(N):
    A.append(int(input()))

pushed = [False] * N
pushed[0] = True
now = 0
cnt = 0
while True:
    next = A[now] - 1
    if pushed[next]:
        cnt = -1
        break

    if next != 1:
        now = next
        cnt += 1

    if next == 1:
        cnt += 1
        break

print(cnt)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
a = [int(input()) for i in range(N)]

pushed = [False] * N
ans = 0
current = 0
while True:
    ans += 1
    current = a[current] - 1
    if pushed[current]:
        ans = -1
        break
    if current == 1:
        break
    pushed[current] = True
print(ans)


Error: TLE

Fixed submission:

N = int(input())
a = [int(input()) for i in range(N)]

pushed = [0]
ans = 0
current = 0
while True:
    ans += 1
    current = a[current] - 1
    if current in pushed:
        ans = -1
        break
    if current == 1:
        break
    pushed.append(current)
print(ans)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = [int(input()) for _ in range(N)]

now = 0
count = 0
while True:
    if count >= N:
        print(-1)
        break

    if now == 1:
        print(count)
        break

    now = A[now] - 1
    count += 1


Error: TLE

Fixed submission:

N = int(input())
A = [int(input()) for _ in range(N)]

now = 0
count = 0
while True:
    if now == 0 and count != 0:
        print(-1)
        break

    if now == 1:
        print(count)
        break

    now = A[now] - 1
    count += 1
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

from collections import defaultdict

N = int(input())
a = [int(input()) for _ in range(N)]
seen_list = defaultdict(int)
n = 1
ans = 0
while True:
    if seen_list[n] == 1:
        print(-1)
        exit()
    else:
        if n == 2:
            print(ans)
            exit()
        else:
            seen_list[n] = 1
            n = a[n - 1]
            ans += 1


Error: TLE

Fixed submission:

N = int(input())
a = [int(input()) for _ in range(N)]
seen_list = []
n = 1
ans = 0
while True:
    if n in seen_list:
        print(-1)
        exit()
    else:
        if n == 2:
            print(ans)
            exit()
        else:
            seen_list.append(n)
            n = a[n - 1]
            ans += 1
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
a = [int(input()) for _ in range(n)]
L = [0] * n
cnt = 0
i = 0
while True:
    if L[i] == 1:
        print(-1)
        break
    else:
        L[i] = 1
        i = a[i] - 1
        cnt += 1
        if i == 1:
            print(cnt)
            break


Error: TLE

Fixed submission:

n = int(input())
a = [int(input()) for _ in range(n)]
L = []
cnt = 0
i = 0
while True:
    if i in L:
        print(-1)
        break
    else:
        L.append(i)
        i = a[i] - 1
        cnt += 1
        if i == 1:
            print(cnt)
            break
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
a_list = [int(input()) for _ in range(N)]

button_history = [1]
current_button = 1
num_manipulation = -1

for i in range(1, N + 1):
    current_button = a_list[current_button - 1]
    if current_button == 2:
        num_manipulation = i
        break

print(num_manipulation)


Error: TLE

Fixed submission:

N = int(input())
a_list = [int(input()) for _ in range(N)]

button_history = [1]
while True:
    next_button = a_list[button_history[-1] - 1]
    if next_button == 2:
        print(len(button_history))
        break
    elif next_button in button_history:
        print(-1)
        break
    else:
        button_history.append(next_button)
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
a = [0] + [int(input()) for _ in range(n)]

pos = 1
for i in range(n):
    pos = a[pos]
    if pos == 2:
        print(i + 1)
        break
else:
    print(-1)


Error: TLE

Fixed submission:

n = int(input())
a = [0] + [int(input()) for _ in range(n)]

pos = 1
cnt = 0
while True:
    cnt += 1
    if a[pos] == 1:
        print(-1)
        break
    elif a[pos] == 2:
        print(cnt)
        break
    pos = a[pos]
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

n = int(input())
buttons = [input() for i in range(n)]
buttons_int = [int(b) - 1 for b in buttons]
button = 0
for count in range(1, n + 1):
    button = buttons_int[button]
    if button == 1:
        print(count)
        exit()
print(-1)


Error: TLE

Fixed submission:

n = int(input())
buttons = [input() for i in range(n)]
buttons_int = [int(b) - 1 for b in buttons]
button = 0
count = 0
history_list = []
i = 0
while i < n:
    if button == i:
        button = buttons_int[i]
        count += 1
        if button == 1:
            print(count)
            exit()
        if i in history_list:
            print(-1)
            exit()
        else:
            history_list.append(i)
        i = 0
    else:
        i += 1
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

def main():
    N = int(input())
    A = [int(input()) for _ in range(N)]
    i = 1
    c = 0
    v = [0] * (N + 1)
    while v[i] == 0:
        if A[i - 1] == 2:
            print(c + 1)
            return
        v[i] = 1
        i = A[i - 1]
        c += 1
    print(-1)


main()


Error: TLE

Fixed submission:

def main():
    N = int(input())
    A = [int(input()) for _ in range(N)]
    i = 1
    c = 0
    v = [0]
    while A[i - 1] not in v:
        if A[i - 1] == 2:
            print(c + 1)
            return
        v.append(i)
        i = A[i - 1]
        c += 1
    print(-1)


main()
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
A = [int(input()) for _ in range(N)]
pushed = [False] * N
pushed[0] = True
button = 0
count = 0
while True:
    count += 1
    button = A[button] - 1
    if button == 1:
        print(count)
        exit()
    if pushed[button]:
        print(-1)
        exit()
    pushed[button] = True


Error: TLE

Fixed submission:

N = int(input())
A = [int(input()) for _ in range(N)]
pushed = [False] * N
pushed[0] = True
button = 0
count = 0
while True:
    count += 1
    button = A[button] - 1
    if button == 1:
        print(count)
        exit()
    if pushed[button]:
        print(-1)
        exit()
Problem p03680 (Python) — buggy submission, verdict: Time Limit Exceeded

N = int(input())
a = [0 for _ in range(N)]
for i in range(N):
    a[i] = int(input())
c = 0
x = 1
while x != 2:
    nex = a[x - 1]
    if not nex:
        c = -1
        break
    else:
        a[x - 1] = False
        c += 1
        x = nex
print(c)


Error: TLE

Fixed submission:

N = int(input())
a = [0 for _ in range(N)]
for i in range(N):
    a[i] = int(input())
c = 0
x = 1
dic = [1]
while 1:
    x = a[x - 1]
    if x == 2:
        c += 1
        break
    elif x in dic:
        c = -1
        break
    else:
        dic.append(x)
        c += 1
print(c)