deploy: 7928aed

Author: yanglbme

en/lc/1570/index.html

@@ -42069,9 +42069,9 @@
       <ul class="md-nav__list">
 
           <li class="md-nav__item">
-  <a href="#solution-1" class="md-nav__link">
+  <a href="#solution-1-hash-map" class="md-nav__link">
     <span class="md-ellipsis">
-      Solution 1
+      Solution 1: Hash Map
     </span>
   </a>
 
@@ -87299,8 +87299,11 @@ <h2 id="description">Description</h2>
 <h2 id="solutions">Solutions</h2>
 <!-- solution:start -->
 
-<h3 id="solution-1">Solution 1</h3>
-<div class="tabbed-set tabbed-alternate" data-tabs="1:5"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Python3</label><label for="__tabbed_1_2">Java</label><label for="__tabbed_1_3">C++</label><label for="__tabbed_1_4">Go</label><label for="__tabbed_1_5">TypeScript</label></div>
+<h3 id="solution-1-hash-map">Solution 1: Hash Map</h3>
+<p>We use a hash map <span class="arithmatex">\(d\)</span> to store non-zero elements, where the key is the index, and the value is the corresponding value. We iterate through <span class="arithmatex">\(\textit{nums}\)</span>, and if <span class="arithmatex">\(\textit{nums}[i]\)</span> is not <span class="arithmatex">\(0\)</span>, we add <span class="arithmatex">\((i, \textit{nums}[i])\)</span> to the hash map <span class="arithmatex">\(d\)</span>.</p>
+<p>When calculating the dot product, we iterate through the hash map with fewer non-zero elements and check if the other hash map contains the corresponding key. If it exists, we multiply the corresponding values and add them to the result.</p>
+<p>The time complexity is <span class="arithmatex">\(O(n)\)</span>, and the space complexity is <span class="arithmatex">\(O(n)\)</span>, where <span class="arithmatex">\(n\)</span> is the length of the array.</p>
+<div class="tabbed-set tabbed-alternate" data-tabs="1:6"><input checked="checked" id="__tabbed_1_1" name="__tabbed_1" type="radio" /><input id="__tabbed_1_2" name="__tabbed_1" type="radio" /><input id="__tabbed_1_3" name="__tabbed_1" type="radio" /><input id="__tabbed_1_4" name="__tabbed_1" type="radio" /><input id="__tabbed_1_5" name="__tabbed_1" type="radio" /><input id="__tabbed_1_6" name="__tabbed_1" type="radio" /><div class="tabbed-labels"><label for="__tabbed_1_1">Python3</label><label for="__tabbed_1_2">Java</label><label for="__tabbed_1_3">C++</label><label for="__tabbed_1_4">Go</label><label for="__tabbed_1_5">TypeScript</label><label for="__tabbed_1_6">Rust</label></div>
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 <div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span></span><span class="normal"> 1</span>
@@ -87614,6 +87617,78 @@ <h3 id="solution-1">Solution 1</h3>
 <span class="cm"> */</span>
 </code></pre></div></td></tr></table></div>
 </div>
+<div class="tabbed-block">
+<div class="highlight"><table class="highlighttable"><tr><td class="linenos"><div class="linenodiv"><pre><span></span><span class="normal"> 1</span>
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+<span class="normal">35</span></pre></div></td><td class="code"><div><pre><span></span><code><span class="k">use</span><span class="w"> </span><span class="n">std</span><span class="p">::</span><span class="n">collections</span><span class="p">::</span><span class="n">HashMap</span><span class="p">;</span>
+
+<span class="cp">#[derive(Clone)]</span>
+<span class="k">struct</span><span class="w"> </span><span class="nc">SparseVector</span><span class="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="nc">HashMap</span><span class="o">&lt;</span><span class="kt">usize</span><span class="p">,</span><span class="w"> </span><span class="kt">i32</span><span class="o">&gt;</span><span class="p">,</span>
+<span class="p">}</span>
+
+<span class="k">impl</span><span class="w"> </span><span class="n">SparseVector</span><span class="w"> </span><span class="p">{</span>
+<span class="w">    </span><span class="k">fn</span><span class="w"> </span><span class="nf">new</span><span class="p">(</span><span class="n">nums</span><span class="p">:</span><span class="w"> </span><span class="nb">Vec</span><span class="o">&lt;</span><span class="kt">i32</span><span class="o">&gt;</span><span class="p">)</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="nc">Self</span><span class="w"> </span><span class="p">{</span>
+<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">d</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">HashMap</span><span class="p">::</span><span class="n">new</span><span class="p">();</span>
+<span class="w">        </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="o">&amp;</span><span class="n">x</span><span class="p">)</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="n">nums</span><span class="p">.</span><span class="n">iter</span><span class="p">().</span><span class="n">enumerate</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
+<span class="w">            </span><span class="k">if</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="o">!=</span><span class="w"> </span><span class="mi">0</span><span class="w"> </span><span class="p">{</span>
+<span class="w">                </span><span class="n">d</span><span class="p">.</span><span class="n">insert</span><span class="p">(</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="n">x</span><span class="p">);</span>
+<span class="w">            </span><span class="p">}</span>
+<span class="w">        </span><span class="p">}</span>
+<span class="w">        </span><span class="n">SparseVector</span><span class="w"> </span><span class="p">{</span><span class="w"> </span><span class="n">d</span><span class="w"> </span><span class="p">}</span>
+<span class="w">    </span><span class="p">}</span>
+
+<span class="w">    </span><span class="k">fn</span><span class="w"> </span><span class="nf">dot_product</span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">,</span><span class="w"> </span><span class="n">vec</span><span class="p">:</span><span class="w"> </span><span class="nc">SparseVector</span><span class="p">)</span><span class="w"> </span><span class="p">-&gt;</span><span class="w"> </span><span class="kt">i32</span><span class="w"> </span><span class="p">{</span>
+<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="p">(</span><span class="n">a</span><span class="p">,</span><span class="w"> </span><span class="n">b</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="p">(</span><span class="o">&amp;</span><span class="bp">self</span><span class="p">.</span><span class="n">d</span><span class="p">,</span><span class="w"> </span><span class="o">&amp;</span><span class="n">vec</span><span class="p">.</span><span class="n">d</span><span class="p">);</span>
+<span class="w">        </span><span class="kd">let</span><span class="w"> </span><span class="k">mut</span><span class="w"> </span><span class="n">ans</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="mi">0</span><span class="p">;</span>
+
+<span class="w">        </span><span class="k">if</span><span class="w"> </span><span class="n">a</span><span class="p">.</span><span class="n">len</span><span class="p">()</span><span class="w"> </span><span class="o">&gt;</span><span class="w"> </span><span class="n">b</span><span class="p">.</span><span class="n">len</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
+<span class="w">            </span><span class="k">return</span><span class="w"> </span><span class="n">vec</span><span class="p">.</span><span class="n">dot_product</span><span class="p">(</span><span class="bp">self</span><span class="p">.</span><span class="n">clone</span><span class="p">());</span>
+<span class="w">        </span><span class="p">}</span>
+
+<span class="w">        </span><span class="k">for</span><span class="w"> </span><span class="p">(</span><span class="o">&amp;</span><span class="n">i</span><span class="p">,</span><span class="w"> </span><span class="o">&amp;</span><span class="n">x</span><span class="p">)</span><span class="w"> </span><span class="k">in</span><span class="w"> </span><span class="n">a</span><span class="p">.</span><span class="n">iter</span><span class="p">()</span><span class="w"> </span><span class="p">{</span>
+<span class="w">            </span><span class="k">if</span><span class="w"> </span><span class="kd">let</span><span class="w"> </span><span class="nb">Some</span><span class="p">(</span><span class="o">&amp;</span><span class="n">y</span><span class="p">)</span><span class="w"> </span><span class="o">=</span><span class="w"> </span><span class="n">b</span><span class="p">.</span><span class="n">get</span><span class="p">(</span><span class="o">&amp;</span><span class="n">i</span><span class="p">)</span><span class="w"> </span><span class="p">{</span>
+<span class="w">                </span><span class="n">ans</span><span class="w"> </span><span class="o">+=</span><span class="w"> </span><span class="n">x</span><span class="w"> </span><span class="o">*</span><span class="w"> </span><span class="n">y</span><span class="p">;</span>
+<span class="w">            </span><span class="p">}</span>
+<span class="w">        </span><span class="p">}</span>
+
+<span class="w">        </span><span class="n">ans</span>
+<span class="w">    </span><span class="p">}</span>
+<span class="p">}</span>
+</code></pre></div></td></tr></table></div>
+</div>
 </div>
 </div>
 <!-- solution:end -->