<p>You are given an array <code>arr</code> which consists of only zeros and ones, divide the array into <strong>three non-empty parts</strong> such that all of these parts represent the same binary value.</p>

<p>If it is possible, return any <code>[i, j]</code> with <code>i + 1 &lt; j</code>, such that:</p>

<ul>
	<li><code>arr[0], arr[1], ..., arr[i]</code> is the first part,</li>
	<li><code>arr[i + 1], arr[i + 2], ..., arr[j - 1]</code> is the second part, and</li>
	<li><code>arr[j], arr[j + 1], ..., arr[arr.length - 1]</code> is the third part.</li>
	<li>All three parts have equal binary values.</li>
</ul>

<p>If it is not possible, return <code>[-1, -1]</code>.</p>

<p>Note that the entire part is used when considering what binary value it represents. For example, <code>[1,1,0]</code> represents <code>6</code> in decimal, not <code>3</code>. Also, leading zeros <strong>are allowed</strong>, so <code>[0,1,1]</code> and <code>[1,1]</code> represent the same value.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<pre><strong>Input:</strong> arr = [1,0,1,0,1]
<strong>Output:</strong> [0,3]
</pre><p><strong class="example">Example 2:</strong></p>
<pre><strong>Input:</strong> arr = [1,1,0,1,1]
<strong>Output:</strong> [-1,-1]
</pre><p><strong class="example">Example 3:</strong></p>
<pre><strong>Input:</strong> arr = [1,1,0,0,1]
<strong>Output:</strong> [0,2]
</pre>
<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>3 &lt;= arr.length &lt;= 3 * 10<sup>4</sup></code></li>
	<li><code>arr[i]</code> is <code>0</code> or <code>1</code></li>
</ul>

class Solution:
    def threeEqualParts(self, arr: List[int]) -> List[int]:
        n = len(arr)
        s = sum(arr)
        if not s:
            return [0, 2]
        if s % 3:
            return [-1, -1]
        z = 0
        while arr[n - 1 - z] == 0:
            z += 1
        j = n - 1
        o = 0
        while o < s // 3:
            o += arr[j]
            j -= 1
        k = j
        while not arr[k]:
            k -= 1
        if j - k < z:
            return [-1, -1]
        j = k + 1 + z
        i = 0
        o = 0
        while o < s // 3:
            o += arr[i]
            i += 1
        k = i
        while k < i + z:
            if arr[k]:
                return [-1, -1]
            k += 1
        i = k - 1
        a = deque(arr[:i + 1])
        b = deque(arr[i + 1:j])
        c = deque(arr[j:])
        while not a[0]:
            a.popleft()
        while not b[0]:
            b.popleft()
        while not c[0]:
            c.popleft()
        if a == b and b == c:
            return [i, j]
        return [-1, -1]
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