lass="code">b</code>, with the same length as <code class="code">a</code>,
    such that <code class="code">b.(i)</code> is the index of the <code class="code">i</code>-th element of <code class="code">a</code> in <code class="code">sort cmp a</code>.
    In other words, <code class="code">map (fun i -&gt; a.(i)) (sort_indices a) = sorted cmp a</code>.
    <code class="code">a</code> is not modified.<br>
<b>Since</b> 1.0<br>
</div>

<pre><span id="VALsort_ranking"><span class="keyword">val</span> sort_ranki