### https://theweeklychallenge.org/blog/perl-weekly-challenge-297/
"""

Task 1: Contiguous Array

Submitted by: [45]Mohammad Sajid Anwar
     __________________________________________________________________

   You are given an array of binary numbers, @binary.

   Write a script to return the maximum length of a contiguous subarray
   with an equal number of 0 and 1.

Example 1

Input: @binary = (1, 0)
Output: 2

(1, 0) is the longest contiguous subarray with an equal number of 0 and 1.

Example 2

Input: @binary = (0, 1, 0)
Output: 2

(1, 0) or (0, 1) is the longest contiguous subarray with an equal number of 0 an
d 1.

Example 3

Input: @binary = (0, 0, 0, 0, 0)
Output: 0

Example 4

Input: @binary = (0, 1, 0, 0, 1, 0)
Output: 4

Task 2: Semi-Ordered Permutation
"""
### solution by pokgopun@gmail.com

from typing import Tuple

def ca(bins: Tuple[int]) -> int:
    l = len(bins)
    if l < 2:
        return  0
    bsm = sum(bins)
    match bsm:
        case 0:
            return 0
        case 1:
            return 2
    c = 0
    for i in range(l - 1):
        sm = bsm
        o = (l - i) % 2
        sm -= bins[l - 1] * o
        for j in range(l - o, i + 1, -2):
            sl = j - i
            if sm == sl / 2:
                if c < sl:
                    c = sl
                    if c >= l - i - o - 2:
                        return c
            sm -= sum(bins[j-2:j])
        bsm -= bins[i]
    return c

import unittest

class TestCA(unittest.TestCase):
    def test(self):
        for inpt, otpt in {
                (1, 0): 2,
                (0, 1, 0): 2,
                (0, 0, 0, 0, 0): 0,
                (0, 1, 0, 0, 1, 0): 4,
                (0, 1, 1, 0, 1, 0): 6,
                (1, 1, 1, 0, 1, 0): 4,
                (0, 1, 1, 0, 1, 0, 1, 1): 6,
                (1, 1, 1, 0, 1, 0, 1, 1): 4,
                (0, 0, 1, 0, 1, 0, 0, 0, 1, 1, 0, 1): 10,
                }.items():
            #print(inpt,otpt)
            self.assertEqual(ca(inpt), otpt)

unittest.main()