an></div>
<div class="line"><a name="l00044"></a><span class="lineno">   44</span>&#160;<span class="comment">// See Tarjan and van Leeuwen (1984). Worst-case analysis of set union</span></div>
<div class="line"><a name="l00045"></a><span class="lineno">   45</span>&#160;<span class="comment">// algorithms. Journal of the ACM 31(2):245-281.</span></div>
<div class="line"><a name="l00046"></a><span class="lineno">   46</span>&#160;<span class="comment">//</span></div>
<div class="line"><a name="l00047"></a><