<p>Given the <strong>API</strong> <code>rand7()</code> that generates a uniform random integer in the range <code>[1, 7]</code>, write a function <code>rand10()</code> that generates a uniform random integer in the range <code>[1, 10]</code>. You can only call the API <code>rand7()</code>, and you shouldn't call any other API. Please <strong>do not</strong> use a language's built-in random API.</p> <p>Each test case will have one <strong>internal</strong> argument <code>n</code>, the number of times that your implemented function <code>rand10()</code> will be called while testing. Note that this is <strong>not an argument</strong> passed to <code>rand10()</code>.</p> <p> </p> <p><strong>Example 1:</strong></p> <pre><strong>Input:</strong> n = 1 <strong>Output:</strong> [2] </pre><p><strong>Example 2:</strong></p> <pre><strong>Input:</strong> n = 2 <strong>Output:</strong> [2,8] </pre><p><strong>Example 3:</strong></p> <pre><strong>Input:</strong> n = 3 <strong>Output:</strong> [3,8,10] </pre> <p> </p> <p><strong>Constraints:</strong></p> <ul> <li><code>1 <= n <= 10<sup>5</sup></code></li> </ul> <p> </p> <p><strong>Follow up:</strong></p> <ul> <li>What is the <a href="https://en.wikipedia.org/wiki/Expected_value" target="_blank">expected value</a> for the number of calls to <code>rand7()</code> function?</li> <li>Could you minimize the number of calls to <code>rand7()</code>?</li> </ul>