number-of-recent-calls.md

<p>Write a class <code>RecentCounter</code> to count recent requests.</p>

<p>It has only one method:&nbsp;<code>ping(int t)</code>, where t represents some time in milliseconds.</p>

<p>Return the number of <code>ping</code>s that have been made from 3000 milliseconds ago until now.</p>

<p>Any ping with time in <code>[t - 3000, t]</code> will count, including the current ping.</p>

<p>It is guaranteed that every call to <code>ping</code> uses a strictly larger value of&nbsp;<code>t</code> than before.</p>

<p>&nbsp;</p>

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

<pre>
<strong>Input: </strong>inputs = <span id="example-input-1-1">[&quot;RecentCounter&quot;,&quot;ping&quot;,&quot;ping&quot;,&quot;ping&quot;,&quot;ping&quot;]</span>, inputs = <span id="example-input-1-2">[[],[1],[100],[3001],[3002]]</span>
<strong>Output: </strong><span id="example-output-1">[null,1,2,3,3]</span></pre>

<p>&nbsp;</p>

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

<ol>
	<li>Each test case will have at most <code>10000</code> calls to <code>ping</code>.</li>
	<li>Each test case will call&nbsp;<code>ping</code> with strictly increasing values of <code>t</code>.</li>
	<li>Each call to ping will have <code>1 &lt;= t &lt;= 10^9</code>.</li>
</ol>

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<p>&nbsp;</p>
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