n><span class="o">::</span><span class="n">vector</span><span class="o">&lt;</span><span class="n">std</span><span class="o">::</span><span class="n">string</span><span class="o">&gt;</span><span class="w"> </span><span class="n">nodes</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">{</span><span class="s">&quot;A&quot;</span><span class="p">,</span><span class="w"> </span><span class="s">&quot;B&quot;</span><span class="p">,</span><span class="w"> </span><span 