Longest palindrome

def longest_palindrom(s):
    t = '#' + '#'.join(s) + '#'
    n = len(t)
    p = [0] * n
    c = 0
    r = 0
    max_len = 0
    center_index = 0

    for i in range(n):
        mirror = 2 * c - i
        if i < r:
            p[i] = min(r - i, p[mirror])
        a = i + p[i] + 1
        b = i - p[i] - 1
        while a < n and b >= 0 and t[a] == t[b]:
            p[i] += 1
            a += 1
            b -= 1
        if i + p[i] > r:
            c = i
            r = i + p[i]
        if p[i] > max_len:
            max_len = p[i]
            center_index = i
    start = (center_index - max_len) // 2
    return s[start:start + max_len]

if __name__ == "__main__":
    print(longest_palindrom(input().strip()))

Test 1

Verdict: ACCEPTED

Test 2

Verdict: ACCEPTED

Test 3

Verdict: ACCEPTED

Test 4

Verdict: ACCEPTED

Test 5

Verdict: ACCEPTED

Test 6

Verdict: ACCEPTED

Test 7

Verdict: ACCEPTED

Test 8

Verdict: ACCEPTED

Test 9

Verdict: ACCEPTED

Test 10

Verdict: ACCEPTED

Test 11

Verdict: ACCEPTED

Test 12

Verdict: ACCEPTED

Test 13

Verdict: ACCEPTED

Test 14

Verdict: ACCEPTED

Test 15

Verdict: ACCEPTED

Test 16

Verdict: ACCEPTED