Occasionally with extended thinking the page seems to hang, this is because the closing tag for the thinking <details> is maybe mixed in with a code block, so it never ends and the actual answer is hidden inside the thinking box. Example chat if it's helpful
The thinking details block is below. At the end of a code block near the end we have this:
<span class="err">```</span><span class="o">&</span><span class="n">lt</span><span class="p">;</span><span class="o">/</span><span class="n">details</span><span class="o">&</span><span class="n">gt</span><span class="p">;</span>
so the close tag got mixed up into the code block.
<details><summary>Thinking</summary>Let's analyze the function and understand what it does before refactoring it:<p></p>
<ol>
<li>The function <code>trim_ways</code> takes a slice of tuples <code>(W, D)</code>
<span class="w"> </span><span class="n">start</span>
<span class="w"> </span><span class="p">.</span><span class="n">zip</span><span class="p">(</span><span class="n">end</span><span class="p">)</span>
<span class="w"> </span><span class="p">.</span><span class="n">filter</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">s</span><span class="p">,</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">*</span><span class="n">e</span><span class="w"> </span><span class="o">>=</span><span class="w"> </span><span class="o">*</span><span class="n">s</span><span class="p">)</span>
<span class="w"> </span><span class="p">.</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">s</span><span class="p">,</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">&</span><span class="n">input</span><span class="p">[</span><span class="n">s</span><span class="o">..=</span><span class="n">e</span><span class="p">])</span>
<span class="w"> </span><span class="p">.</span><span class="n">unwrap_or_default</span><span class="p">()</span>
<span class="p">}</span>
.....
<span class="w"> </span><span class="n">seen</span><span class="p">.</span><span class="n">extend</span><span class="p">(</span><span class="n">trimmed</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">w</span><span class="p">,</span><span class="w"> </span><span class="n">_</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="n">w</span><span class="p">.</span><span class="n">index</span><span class="p">()));</span>
<span class="w"> </span><span class="n">trimmed</span>
<span class="p">}</span>
<span class="err">```</span><span class="o">&</span><span class="n">lt</span><span class="p">;</span><span class="o">/</span><span class="n">details</span><span class="o">&</span><span class="n">gt</span><span class="p">;</span>
<span class="n">Here</span><span class="o">&</span>#<span class="n">x27</span><span class="p">;</span><span class="n">s</span><span class="w"> </span><span class="n">the</span><span class="w"> </span><span class="n">refactored</span><span class="w"> </span><span class="n">code</span>:
<span class="err">```</span><span class="n">rust</span>
<span class="k">fn</span> <span class="nf">trim_slice_by_predicate</span><span class="o"><'</span><span class="na">a</span><span class="p">,</span><span class="w"> </span><span class="n">T</span><span class="o">></span><span class="p">(</span>
<span class="w"> </span><span class="n">input</span>: <span class="kp">&</span><span class="o">'</span><span class="na">a</span> <span class="p">[</span><span class="n">T</span><span class="p">],</span><span class="w"> </span>
<span class="w"> </span><span class="n">predicate</span>: <span class="nc">impl</span><span class="w"> </span><span class="nb">Fn</span><span class="p">(</span><span class="o">&</span><span class="n">T</span><span class="p">)</span><span class="w"> </span>-> <span class="kt">bool</span>
<span class="p">)</span><span class="w"> </span>-> <span class="kp">&</span><span class="o">'</span><span class="na">a</span> <span class="p">[</span><span class="n">T</span><span class="p">]</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">start</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">input</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">position</span><span class="p">(</span><span class="o">|</span><span class="n">item</span><span class="o">|</span><span class="w"> </span><span class="n">predicate</span><span class="p">(</span><span class="n">item</span><span class="p">));</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">end</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">input</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">rposition</span><span class="p">(</span><span class="o">|</span><span class="n">item</span><span class="o">|</span><span class="w"> </span><span class="n">predicate</span><span class="p">(</span><span class="n">item</span><span class="p">));</span>
<span class="w"> </span><span class="n">start</span>
<span class="w"> </span><span class="p">.</span><span class="n">zip</span><span class="p">(</span><span class="n">end</span><span class="p">)</span>
<span class="w"> </span><span class="p">.</span><span class="n">filter</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">s</span><span class="p">,</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">*</span><span class="n">e</span><span class="w"> </span><span class="o">>=</span><span class="w"> </span><span class="o">*</span><span class="n">s</span><span class="p">)</span>
<span class="w"> </span><span class="p">.</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">s</span><span class="p">,</span><span class="w"> </span><span class="n">e</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">&</span><span class="n">input</span><span class="p">[</span><span class="n">s</span><span class="o">..=</span><span class="n">e</span><span class="p">])</span>
<span class="w"> </span><span class="p">.</span><span class="n">unwrap_or_default</span><span class="p">()</span>
<span class="p">}</span>
<span class="k">fn</span> <span class="nf">trim_ways</span><span class="o"><'</span><span class="na">a</span><span class="p">,</span><span class="w"> </span><span class="n">W</span>: <span class="nc">Indexed</span><span class="p">,</span><span class="w"> </span><span class="n">D</span>: <span class="nc">Cost</span><span class="o">></span><span class="p">(</span>
<span class="w"> </span><span class="n">input</span>: <span class="kp">&</span><span class="o">'</span><span class="na">a</span> <span class="p">[(</span><span class="n">W</span><span class="p">,</span><span class="w"> </span><span class="n">D</span><span class="p">)],</span>
<span class="w"> </span><span class="n">is_way_useful</span>: <span class="nc">impl</span><span class="w"> </span><span class="nb">Fn</span><span class="p">(</span><span class="o">&</span><span class="n">W</span><span class="p">)</span><span class="w"> </span>-> <span class="kt">bool</span><span class="p">,</span>
<span class="w"> </span><span class="n">min_segment_length</span>: <span class="nc">D</span><span class="p">,</span>
<span class="w"> </span><span class="n">seen</span>: <span class="kp">&</span><span class="nc">mut</span><span class="w"> </span><span class="n">HashSet</span><span class="o"><</span><span class="n">W</span>::<span class="n">Index</span><span class="o">></span><span class="p">,</span>
<span class="p">)</span><span class="w"> </span>-> <span class="kp">&</span><span class="o">'</span><span class="na">a</span> <span class="p">[(</span><span class="n">W</span><span class="p">,</span><span class="w"> </span><span class="n">D</span><span class="p">)]</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">is_desired</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">|</span><span class="p">(</span><span class="n">w</span><span class="p">,</span><span class="w"> </span><span class="n">_</span><span class="p">)</span>: <span class="kp">&</span><span class="p">(</span><span class="n">W</span><span class="p">,</span><span class="w"> </span><span class="n">D</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">!</span><span class="n">seen</span><span class="p">.</span><span class="n">contains</span><span class="p">(</span><span class="o">&</span><span class="n">w</span><span class="p">.</span><span class="n">index</span><span class="p">())</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">is_way_useful</span><span class="p">(</span><span class="n">w</span><span class="p">);</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">trimmed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">trim_slice_by_predicate</span><span class="p">(</span><span class="n">input</span><span class="p">,</span><span class="w"> </span><span class="n">is_desired</span><span class="p">);</span>
<span class="w"> </span><span class="c1">// If trimmed is not empty but too short, try trimming only by the first condition</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">trimmed</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="k">if</span><span class="w"> </span><span class="o">!</span><span class="n">trimmed</span><span class="p">.</span><span class="n">is_empty</span><span class="p">()</span><span class="w"> </span><span class="o">&&</span><span class="w"> </span><span class="n">trimmed</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">_</span><span class="p">,</span><span class="w"> </span><span class="n">d</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">*</span><span class="n">d</span><span class="p">).</span><span class="n">sum</span>::<span class="o"><</span><span class="n">D</span><span class="o">></span><span class="p">()</span><span class="w"> </span><span class="o"><</span><span class="w"> </span><span class="n">min_segment_length</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="n">is_not_seen</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="o">|</span><span class="p">(</span><span class="n">w</span><span class="p">,</span><span class="w"> </span><span class="n">_</span><span class="p">)</span>: <span class="kp">&</span><span class="p">(</span><span class="n">W</span><span class="p">,</span><span class="w"> </span><span class="n">D</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="o">!</span><span class="n">seen</span><span class="p">.</span><span class="n">contains</span><span class="p">(</span><span class="o">&</span><span class="n">w</span><span class="p">.</span><span class="n">index</span><span class="p">());</span>
<span class="w"> </span><span class="n">trim_slice_by_predicate</span><span class="p">(</span><span class="n">input</span><span class="p">,</span><span class="w"> </span><span class="n">is_not_seen</span><span class="p">)</span>
<span class="w"> </span><span class="p">}</span><span class="w"> </span><span class="k">else</span><span class="w"> </span><span class="p">{</span>
<span class="w"> </span><span class="n">trimmed</span>
<span class="w"> </span><span class="p">};</span>
<span class="w"> </span><span class="n">seen</span><span class="p">.</span><span class="n">extend</span><span class="p">(</span><span class="n">trimmed</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">map</span><span class="p">(</span><span class="o">|</span><span class="p">(</span><span class="n">w</span><span class="p">,</span><span class="w"> </span><span class="n">_</span><span class="p">)</span><span class="o">|</span><span class="w"> </span><span class="n">w</span><span class="p">.</span><span class="n">index</span><span class="p">()));</span>
<span class="w"> </span><span class="n">trimmed</span>
<span class="p">}</span>
</code></pre></div></details>
The actual answer should come after the thinking is done.
