Problem p03061 (python)

Fixed submission:
def gcd(a, b):
    if b == 0:
        return a
    else:
        return gcd(b, a%b)

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    left = [0] * (N + 1)
    right = [0] * (N + 1)
    left[0] = 0
    right[N] = 0
    for i in range(1, N+1):
        left[i] = gcd(left[i - 1], arr[i - 1])
    for i in range(N - 1, 0, -1):
        right[i] = gcd(right[i + 1], arr[i])
    max_gcd = 0
    for i in range(N):
        max_gcd = max(max_gcd, gcd(left[i], right[i+1]))
    print str(max_gcd)

if __name__ == '__main__':
    solve()

Buggy submission (verdict: Runtime Error):
def gcd(a, b):
    if a == b or b == 0:
        return a
    elif a == 0:
        return b
    elif a > b:
        return gcd(a - b, b)
    elif a < b:
        return gcd(a, b - a)

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    left = [0] * (N + 1)
    right = [0] * (N + 1)
    left[0] = 0
    right[N] = 0
    for i in range(1, N+1):
        left[i] = gcd(left[i - 1], arr[i - 1])
    for i in range(N - 1, 0, -1):
        right[i] = gcd(right[i + 1], arr[i])
    max_gcd = 0
    for i in range(N):
        max_gcd = max(max_gcd, gcd(left[i], right[i+1]))
    print str(max_gcd)

if __name__ == '__main__':
    solve()

Buggy submission (verdict: Runtime Error):
def gcd(a, b):
    if a == b or b == 0:
        return a
    elif b == 0:
        return a
    elif a > b:
        return gcd(a - b, b)
    elif a < b:
        return gcd(a, b - a)

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    left = [0] * (N + 1)
    right = [0] * (N + 1)
    left[0] = 0
    right[N] = 0
    for i in range(1, N+1):
        left[i] = gcd(left[i - 1], arr[i - 1])
    for i in range(N - 1, 0, -1):
        right[i] = gcd(right[i + 1], arr[i])
    max_gcd = 0
    for i in range(N):
        max_gcd = max(max_gcd, gcd(left[i], right[i+1]))
    print str(max_gcd)

if __name__ == '__main__':
    solve()

Buggy submission (verdict: Runtime Error):
def gcd(a, b):
    if a == b or b == 0:
        return a
    elif b == 0:
        return a
    elif a > b:
        return gcd(a - b, b)
    elif a < b:
        return gcd(a, b - a)

def gcd_arr(arr, N):
    if N == 2:
        return gcd(arr[0], arr[1])
    elif N == 1:
        return arr[0]
    else:
        mid = N // 2
        return gcd(gcd_arr(arr[:mid], mid), gcd_arr(arr[mid:], N-mid))

def gcd_arr_with_rm(arr, N, remove = 0):
    return gcd_arr(arr[0:remove] + arr[(remove+1):], N - 1)

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    max_gcd = 1
    for j in range(N):
        tmp = gcd_arr_with_rm(arr, N, remove = j)
        if tmp > max_gcd:
            max_gcd = tmp
    print str(max_gcd)

if __name__ == '__main__':
    solve()

Buggy submission (verdict: Runtime Error):
import math

def gcd_arr(arr, N, remove = 0):
    if remove == 0:
        _gcd = arr[1]
    else:
        _gcd = arr[0]
    for i in range(N):
        if i != remove:
            _gcd = math.gcd(_gcd, arr[i])
    return _gcd

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    max_gcd = 1
    for j in range(N):
        tmp = gcd_arr(arr, N, remove = j)
        if tmp > max_gcd:
            max_gcd = tmp
    print str(max_gcd)

if __name__ == '__main__':
    solve()

Buggy submission (verdict: Runtime Error):
def gcd(a, b):
    if a == b:
        return a
    elif a > b:
        return gcd(a - b, b)
    elif a < b:
        return gcd(a, b - a)

def gcd_arr(arr, N, remove = 0):
    if remove == 0:
        _gcd = arr[1]
    else:
        _gcd = arr[0]
    for i in range(N):
        if i != remove:
            _gcd = gcd(_gcd, arr[i])
    return _gcd

def solve():
    N = int(raw_input())
    arr = [int(_) for _ in raw_input().split()]
    max_gcd = 1
    for i in range(N):
        tmp = gcd_arr(arr, N, remove = i)
        if tmp > max_gcd:
            max_gcd = tmp
    print str(max_gcd)

if __name__ == '__main__':
    solve()