implement-rand10-using-rand7.md

<p>Given a function <code>rand7</code> which generates a uniform random integer in the range 1 to 7, write a function <code>rand10</code>&nbsp;which generates a uniform random integer in the range 1 to 10.</p>

<p>Do NOT use system&#39;s <code>Math.random()</code>.</p>

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<p>&nbsp;</p>

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<p><strong>Example 1:</strong></p>

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<strong>Input: </strong><span id="example-input-1-1">1</span>
<strong>Output: </strong><span id="example-output-1">[7]</span>
</pre>

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<p><strong>Example 2:</strong></p>

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<strong>Input: </strong><span id="example-input-2-1">2</span>
<strong>Output: </strong><span id="example-output-2">[8,4]</span>
</pre>

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<p><strong>Example 3:</strong></p>

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<strong>Input: </strong><span id="example-input-3-1">3</span>
<strong>Output: </strong><span id="example-output-3">[8,1,10]</span>
</pre>

<p>&nbsp;</p>

<p><strong>Note:</strong></p>

<ol>
	<li><code>rand7</code> is predefined.</li>
	<li>Each testcase has one argument:&nbsp;<code>n</code>, the number of times that <code>rand10</code> is called.</li>
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<p>&nbsp;</p>

<p><strong>Follow up:</strong></p>

<ol>
	<li>What is the <a href="https://en.wikipedia.org/wiki/Expected_value" target="_blank">expected value</a>&nbsp;for the number of calls to&nbsp;<code>rand7()</code>&nbsp;function?</li>
	<li>Could you minimize the number of calls to <code>rand7()</code>?</li>
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