<p>You are given a string <code>word</code> and an integer <code>k</code>.</p>

<p>A substring <code>s</code> of <code>word</code> is <strong>complete</strong> if:</p>

<ul>
	<li>Each character in <code>s</code> occurs <strong>exactly</strong> <code>k</code> times.</li>
	<li>The difference between two adjacent characters is <strong>at most</strong> <code>2</code>. That is, for any two adjacent characters <code>c1</code> and <code>c2</code> in <code>s</code>, the absolute difference in their positions in the alphabet is <strong>at most</strong> <code>2</code>.</li>
</ul>

<p>Return <em>the number of <strong>complete </strong>substrings of</em> <code>word</code>.</p>

<p>A <strong>substring</strong> is a <strong>non-empty</strong> contiguous sequence of characters in a string.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>

<pre>
<strong>Input:</strong> word = &quot;igigee&quot;, k = 2
<strong>Output:</strong> 3
<strong>Explanation:</strong> The complete substrings where each character appears exactly twice and the difference between adjacent characters is at most 2 are: <u><strong>igig</strong></u>ee, igig<u><strong>ee</strong></u>, <u><strong>igigee</strong></u>.
</pre>

<p><strong class="example">Example 2:</strong></p>

<pre>
<strong>Input:</strong> word = &quot;aaabbbccc&quot;, k = 3
<strong>Output:</strong> 6
<strong>Explanation:</strong> The complete substrings where each character appears exactly three times and the difference between adjacent characters is at most 2 are: <strong><u>aaa</u></strong>bbbccc, aaa<u><strong>bbb</strong></u>ccc, aaabbb<u><strong>ccc</strong></u>, <strong><u>aaabbb</u></strong>ccc, aaa<u><strong>bbbccc</strong></u>, <u><strong>aaabbbccc</strong></u>.
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li><code>1 &lt;= word.length &lt;= 10<sup>5</sup></code></li>
	<li><code>word</code> consists only of lowercase English letters.</li>
	<li><code>1 &lt;= k &lt;= word.length</code></li>
</ul>

class Solution:
    def countCompleteSubstrings(self, word: str, k: int) -> int:
        ####
                        
        def helper(sz):
            cnt = collections.Counter()
            targetUnique = sz // k
            l, r = 0 ,0
            N = len(word)
            unique = 0
            cur = 0
            while l <= N - sz:
                # get a window
                while r - l < sz and r < N:
                    if r > l and abs(ord(word[r]) - ord(word[r-1])) > 2:
                        # new window
                        l = r
                        cnt = collections.Counter()
                        unique = 0
                    else:
                        cnt[word[r]] += 1
                        unique += cnt[word[r]] == k
                        r += 1
                # if r == N:
                #     print("in the loop", l, r, unique)
                if r - l == sz and unique == targetUnique:
                    cur += 1

                unique -= cnt[word[l]] == k
                cnt[word[l]] -= 1
                l += 1

            return cur

        res = 0
        N = len(word)
        for chars in range(1, min(len(word)//k, 26) + 1):
            sz = chars * k
            # cnt = collections.Counter()
            # l, r = 0 ,0
            curRes = helper(sz)
            # print(chars, curRes)
            res += curRes
        return res


7001