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43 lines
1.9 KiB
HTML
43 lines
1.9 KiB
HTML
<p>You are given an integer <code>n</code>.</p>
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<p>A string <code>s</code> is called <strong>good </strong>if it contains only lowercase English characters <strong>and</strong> it is possible to rearrange the characters of <code>s</code> such that the new string contains <code>"leet"</code> as a <strong>substring</strong>.</p>
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<p>For example:</p>
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<ul>
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<li>The string <code>"lteer"</code> is good because we can rearrange it to form <code>"leetr"</code> .</li>
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<li><code>"letl"</code> is not good because we cannot rearrange it to contain <code>"leet"</code> as a substring.</li>
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</ul>
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<p>Return <em>the <strong>total</strong> number of good strings of length </em><code>n</code>.</p>
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<p>Since the answer may be large, return it <strong>modulo </strong><code>10<sup>9</sup> + 7</code>.</p>
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<p>A <strong>substring</strong> is a contiguous sequence of characters within a string.</p>
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<div class="notranslate" style="all: initial;"> </div>
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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> n = 4
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<strong>Output:</strong> 12
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<strong>Explanation:</strong> The 12 strings which can be rearranged to have "leet" as a substring are: "eelt", "eetl", "elet", "elte", "etel", "etle", "leet", "lete", "ltee", "teel", "tele", and "tlee".
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</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> n = 10
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<strong>Output:</strong> 83943898
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<strong>Explanation:</strong> The number of strings with length 10 which can be rearranged to have "leet" as a substring is 526083947580. Hence the answer is 526083947580 % (10<sup>9</sup> + 7) = 83943898.
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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 <= n <= 10<sup>5</sup></code></li>
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</ul>
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