Editing 2438 - Pal (section)

== Rezolvare ==
<syntaxhighlight lang="python" line>
def is_palindrome(num):
    return str(num) == str(num)[::-1]

def next_palindrome(num):
    num += 1
    while not is_palindrome(num):
        num += 1
    return num

def prev_palindrome(num):
    num -= 1
    while not is_palindrome(num):
        num -= 1
    return num

def find_longest_magic_sequence(palindromes):
    n = len(palindromes)
    dp = [[0] * n for _ in range(n)]
    max_length = 1

    for i in range(n):
        dp[i][i] = 1

    for length in range(2, n + 1):
        for i in range(n - length + 1):
            j = i + length - 1
            if length == 2 and palindromes[i] == palindromes[j]:
                dp[i][j] = 2
                max_length = max(max_length, 2)
            elif palindromes[i] == palindromes[j] and dp[i + 1][j - 1] == length - 2:
                dp[i][j] = length
                max_length = max(max_length, length)

    return max_length

def main():
    with open("pal.in", "r") as fin:
        p = int(fin.readline())
        n = int(fin.readline())
        numbers = list(map(int, fin.readline().split()))

    if p == 1:
        correct_numbers = [next_palindrome(num) for num in numbers]
        with open("pal.out", "w") as fout:
            fout.write(" ".join(map(str, correct_numbers)))
    elif p == 2:
        max_length = find_longest_magic_sequence(numbers)
        with open("pal.out", "w") as fout:
            fout.write(f"{max_length}\n")
    elif p == 3:
        max_length = find_longest_magic_sequence(numbers)
        max_palindromes = []
        for i in range(n):
            for j in range(i + 1, n):
                if numbers[i] == numbers[j]:
                    palindromes = [numbers[k] for k in range(i, j + 1)]
                    if find_longest_magic_sequence(palindromes) == max_length:
                        max_palindromes = palindromes
        with open("pal.out", "w") as fout:
            fout.write(" ".join(map(str, max_palindromes)))

if __name__ == "__main__":
    main()

</syntaxhighlight>