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39 lines
1.9 KiB
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39 lines
1.9 KiB
HTML
<p>You are given a string <code>s</code> consisting of lowercase letters and an integer <code>k</code>. We call a string <code>t</code> <strong>ideal</strong> if the following conditions are satisfied:</p>
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<ul>
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<li><code>t</code> is a <strong>subsequence</strong> of the string <code>s</code>.</li>
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<li>The absolute difference in the alphabet order of every two <strong>adjacent</strong> letters in <code>t</code> is less than or equal to <code>k</code>.</li>
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</ul>
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<p>Return <em>the length of the <strong>longest</strong> ideal string</em>.</p>
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<p>A <strong>subsequence</strong> is a string that can be derived from another string by deleting some or no characters without changing the order of the remaining characters.</p>
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<p><strong>Note</strong> that the alphabet order is not cyclic. For example, the absolute difference in the alphabet order of <code>'a'</code> and <code>'z'</code> is <code>25</code>, not <code>1</code>.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<pre>
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<strong>Input:</strong> s = "acfgbd", k = 2
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<strong>Output:</strong> 4
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<strong>Explanation:</strong> The longest ideal string is "acbd". The length of this string is 4, so 4 is returned.
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Note that "acfgbd" is not ideal because 'c' and 'f' have a difference of 3 in alphabet order.</pre>
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<p><strong class="example">Example 2:</strong></p>
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<pre>
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<strong>Input:</strong> s = "abcd", k = 3
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<strong>Output:</strong> 4
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<strong>Explanation:</strong> The longest ideal string is "abcd". The length of this string is 4, so 4 is returned.
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</pre>
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<p> </p>
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<p><strong>Constraints:</strong></p>
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<ul>
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<li><code>1 <= s.length <= 10<sup>5</sup></code></li>
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<li><code>0 <= k <= 25</code></li>
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<li><code>s</code> consists of lowercase English letters.</li>
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</ul>
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