Buggy python submission (verdict: Time Limit Exceeded):
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    B = [0]
    i = 1; j = 0
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        B.append(min(j, i))
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = max(B)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)


Fixed submission:
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    B = [0]
    i = 1; j = 0
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        B.append(min(j, i))
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = max(B)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    i = 1; j = 0
    A[0] = length
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = 0
    for a in A:
        if a <= length//2:
            ans = max(ans, a)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)


Fixed submission:
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    B = [0]
    i = 1; j = 0
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        B.append(min(j, i))
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = max(B)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
def z_algolithm(S):
    length = len(S)
    A = [0]*length
    i = 1; j = 0
    A[0] = length
    while i < length:
        while i+j < length and S[j] == S[i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = 0
    for a in A:
        if a <= length//2:
            ans = max(ans, a)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S[x:]) for x in range(N)])
print(ans)

Fixed submission:
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    B = [0]
    i = 1; j = 0
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        B.append(min(j, i))
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = max(B)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)

Buggy python submission (verdict: Time Limit Exceeded):
n = int(input())
S = input()
k = n//2

for l in range(k, 0, -1):
    word = S[0:l]

    for i in range(n):
        if S[l+i:].find(word) >= 0:
            print(l)
            exit()

        if i + 2*l > n:
            break
        word = word[1:] + S[l+i]

print(0)

Fixed submission:
def z_algolithm(S, x):
    length = len(S) - x
    A = [0]*length
    B = [0]
    i = 1; j = 0
    while i < length:
        while i+j < length and S[x+j] == S[x+i+j]:
            j += 1
        if not j:
            i += 1
            continue
        A[i] = j
        B.append(min(j, i))
        k = 1
        while k < length - i  and k + A[k] < j :
            A[i+k] = A[k]
            k += 1
        i += k
        j -= k
    ans = max(B)
    return ans

N = int(input())
S = input()
ans = max([z_algolithm(S, x) for x in range(N)])
print(ans)