ial">;</span></pre></div>
<div class="refsect1">
<a name="idp97965216"></a><h2>Description</h2>
<p>The <code class="computeroutput">reduce_by_key()</code> algorithm performs reduction for each contiguous subsequence of values determinate by equivalent keys.</p>
<p>Returns a pair of iterators at the end of the ranges [<code class="computeroutput">keys_result</code>, keys_result_last) and [<code class="computeroutput">values_result</code>, <code class="computeroutput">values_result_last</code>).</p>
<p>If no 