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43 lines
1.5 KiB
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43 lines
1.5 KiB
HTML
<p>You are given 2 <strong>positive</strong> integers <code>l</code> and <code>r</code>. For any number <code>x</code>, all positive divisors of <code>x</code> <em>except</em> <code>x</code> are called the <strong>proper divisors</strong> of <code>x</code>.</p>
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<p>A number is called <strong>special</strong> if it has exactly 2 <strong>proper divisors</strong>. For example:</p>
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<ul>
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<li>The number 4 is <em>special</em> because it has proper divisors 1 and 2.</li>
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<li>The number 6 is <em>not special</em> because it has proper divisors 1, 2, and 3.</li>
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</ul>
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<p>Return the count of numbers in the range <code>[l, r]</code> that are <strong>not</strong> <strong>special</strong>.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<div class="example-block">
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<p><strong>Input:</strong> <span class="example-io">l = 5, r = 7</span></p>
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<p><strong>Output:</strong> <span class="example-io">3</span></p>
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<p><strong>Explanation:</strong></p>
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<p>There are no special numbers in the range <code>[5, 7]</code>.</p>
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</div>
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<p><strong class="example">Example 2:</strong></p>
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<div class="example-block">
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<p><strong>Input:</strong> <span class="example-io">l = 4, r = 16</span></p>
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<p><strong>Output:</strong> <span class="example-io">11</span></p>
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<p><strong>Explanation:</strong></p>
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<p>The special numbers in the range <code>[4, 16]</code> are 4 and 9.</p>
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</div>
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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 <= l <= r <= 10<sup>9</sup></code></li>
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</ul>
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