Problem p03739 (python)

Fixed submission:
import itertools

def sign(num):
    if num < 0:
        return -1
    elif num > 0:
        return 1
    else:
        return 0

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

signs = [-1,1]
a_sum = 0
changes_1 = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes_1 += abs(a_sum) + 1
        a_sum = signs[i%2]

signs = [1,-1]
a_sum = 0
changes_2 = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes_2 += abs(a_sum) + 1
        a_sum = signs[i%2]

print(min(changes_1,changes_2))

Buggy submission (verdict: Runtime Error):
import itertools

def sign(num):
    if num < 0:
        return -1
    elif num > 0:
        return 1
    else:
        return 0

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

signs = [-1,1]
a_sum = 0
changes_1 = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes += abs(a_sum) + 1
        a_sum = signs[i%2]

signs = [1,-1]
a_sum = 0
changes_2 = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes += abs(a_sum) + 1
        a_sum = signs[i%2]

print(min(changes_1,changes_2))

#
# for i, sum_i in enumerate(a_sum):
#     if i == 0:
#         signs = [sign(sum_i), -sign(sum_i)]
#     elif sign(sum_i) != signs[i%2]:
#         a_sum[i:] = [num + (abs(sum_i) + 1) * signs[i%2] for num in a_sum[i:]]
#         changes += abs(sum_i) + 1
#     # print(a_sum)
# print(changes)

Buggy submission (verdict: Runtime Error):
import itertools

def sign(num):
    if num < 0:
        return -1
    elif num > 0:
        return 1
    else:
        return 0

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

a_sum = [a_i[0]]
for i, a in enumerate(a_i[1:]):
    i += 1
    a_sum.append(a_sum[-1]+a)

signs = [1, -1]
for i, sum_i in enumerate(a_sum):
    if sum_i != 0 && i%2 == 0:
        signs = [sign(sum_i), -sign(sum_i)]
        break
    elif sum_i != 0 && i%2 == 1:
        signs = [-sign(sum_i), sign(sum_i)]
        break

a_sum = 0
changes = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes += abs(a_sum) + 1
        a_sum = signs[i%2]
print(changes)

#
# for i, sum_i in enumerate(a_sum):
#     if i == 0:
#         signs = [sign(sum_i), -sign(sum_i)]
#     elif sign(sum_i) != signs[i%2]:
#         a_sum[i:] = [num + (abs(sum_i) + 1) * signs[i%2] for num in a_sum[i:]]
#         changes += abs(sum_i) + 1
#     # print(a_sum)
# print(changes)

Buggy submission (verdict: Runtime Error):
import itertools

def sign(num):
    if num < 0:
        return -1
    elif num > 0:
        return 1
    else:
        return 0

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

a_sum = [a_i[0]]
for i, a in enumerate(a_i[1:]):
    i += 1
    a_sum.append(a_sum[-1]+a)

signs = [1, -1]
for i, sum_i in enumerate(a_sum):
    if sum_i != 0:
        signs[i%2] = sign(sum_i)
        signs[i%2+1] = -sign(sum_i)
        break

a_sum = 0
changes = 0
for i, a in enumerate(a_i):
    a_sum += a
    if sign(a_sum) != signs[i%2]:
        changes += abs(a_sum) + 1
        a_sum = signs[i%2]
print(changes)

#
# for i, sum_i in enumerate(a_sum):
#     if i == 0:
#         signs = [sign(sum_i), -sign(sum_i)]
#     elif sign(sum_i) != signs[i%2]:
#         a_sum[i:] = [num + (abs(sum_i) + 1) * signs[i%2] for num in a_sum[i:]]
#         changes += abs(sum_i) + 1
#     # print(a_sum)
# print(changes)

Buggy submission (verdict: Runtime Error):
import itertools

def sign(num):
    if num < 0:
        return -1
    elif num > 0:
        return 1
    else:
        return 0

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

a_sum = [a_i[0]]
for i, a in enumerate(a_i[1:]):
    i += 1
    a_sum.append(a_sum[-1]+a)

signs = [0, 0]
changes = 0

for i, sum_i in enumerate(a_sum):
    if sum_i != 0:
        signs[i%2] = sign(sum_i)
        signs[i%2+1] = -sign(sum_i)
        break

if signs == [0, 0]:
    signs = [1, -1]

for i, sum_i in enumerate(a_sum):
    if i == 0:
        signs = [sign(sum_i), -sign(sum_i)]
    elif sign(sum_i) != signs[i%2]:
        a_sum[i:] = [num + (abs(sum_i) + 1) * signs[i%2] for num in a_sum[i:]]
        changes += abs(sum_i) + 1
    # print(a_sum)
print(changes)