<p>You are given a string <code>word</code> and an array of strings <code>forbidden</code>.</p>

<p>A string is called <strong>valid</strong> if none of its substrings are present in <code>forbidden</code>.</p>

<p>Return <em>the length of the <strong>longest valid substring</strong> of the string </em><code>word</code>.</p>

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

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

<pre>
<strong>Input:</strong> word = &quot;cbaaaabc&quot;, forbidden = [&quot;aaa&quot;,&quot;cb&quot;]
<strong>Output:</strong> 4
<strong>Explanation:</strong> There are 11 valid substrings in word: &quot;c&quot;, &quot;b&quot;, &quot;a&quot;, &quot;ba&quot;, &quot;aa&quot;, &quot;bc&quot;, &quot;baa&quot;, &quot;aab&quot;, &quot;ab&quot;, &quot;abc&quot; and &quot;aabc&quot;. The length of the longest valid substring is 4. 
It can be shown that all other substrings contain either &quot;aaa&quot; or &quot;cb&quot; as a substring. </pre>

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

<pre>
<strong>Input:</strong> word = &quot;leetcode&quot;, forbidden = [&quot;de&quot;,&quot;le&quot;,&quot;e&quot;]
<strong>Output:</strong> 4
<strong>Explanation:</strong> There are 11 valid substrings in word: &quot;l&quot;, &quot;t&quot;, &quot;c&quot;, &quot;o&quot;, &quot;d&quot;, &quot;tc&quot;, &quot;co&quot;, &quot;od&quot;, &quot;tco&quot;, &quot;cod&quot;, and &quot;tcod&quot;. The length of the longest valid substring is 4.
It can be shown that all other substrings contain either &quot;de&quot;, &quot;le&quot;, or &quot;e&quot; as a substring. 
</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;= forbidden.length &lt;= 10<sup>5</sup></code></li>
	<li><code>1 &lt;= forbidden[i].length &lt;= 10</code></li>
	<li><code>forbidden[i]</code> consists only of lowercase English letters.</li>
</ul>

class Solution:
    def longestValidSubstring(self, word: str, forbidden: List[str]) -> int:
        # if len(word) == 1 and word not in forbidden:
        #     return 1

        # l, r = 0,1
        # ans = 0
        # running_len = 0

        # while r < len(word):
        #     temp = 0
        #     for string in forbidden:
        #         if string in word[l:r]:
        #             temp = 1
        #             break

        #     if temp == 0:
        #         running_len += 1
        #         r += 1
        #     else:
        #         l += 1

        n = len(word)
        dic = {}
        m = 0

        for string in forbidden:
            dic[string] = 1
            m = max(m, len(string))

        r = n
        ans = 0

        for i in range(n-1, -1, -1):
            temp = ""
            j = i
            while j < n and j< i + m and j<= r:
                temp += word[j]
                if temp in dic.keys():
                    r = j
                    break
                j+=1
            ans = max(ans, r-i)
        return ans


        
980