mirror of
https://gitee.com/coder-xiaomo/leetcode-problemset
synced 2025-11-04 19:53:12 +08:00
148 lines
5.3 KiB
HTML
148 lines
5.3 KiB
HTML
<p>表：<code>ProductPurchases</code></p>
|
||
|
||
<pre>
|
||
+-------------+------+
|
||
| Column Name | Type |
|
||
+-------------+------+
|
||
| user_id | int |
|
||
| product_id | int |
|
||
| quantity | int |
|
||
+-------------+------+
|
||
(user_id, product_id) 是这张表的唯一主键。
|
||
每一行代表用户以特定数量购买的一种产品。
|
||
</pre>
|
||
|
||
<p>表：<code>ProductInfo</code></p>
|
||
|
||
<pre>
|
||
+-------------+---------+
|
||
| Column Name | Type |
|
||
+-------------+---------+
|
||
| product_id | int |
|
||
| category | varchar |
|
||
| price | decimal |
|
||
+-------------+---------+
|
||
product_id 是这张表的唯一主键。
|
||
每一行表示一件商品的类别和价格。
|
||
</pre>
|
||
|
||
<p>亚马逊想要了解不同产品类别的购物模式。编写一个解决方案：</p>
|
||
|
||
<ol>
|
||
<li>查找所有 <strong>类别对</strong>（其中 <code>category1</code> < <code>category2</code>）</li>
|
||
<li>对于 <strong>每个类别对</strong>，确定 <strong>同时</strong> 购买了两类别产品的 <strong>不同用户</strong> 数量</li>
|
||
</ol>
|
||
|
||
<p>如果至少有 <code>3</code> 个不同的客户购买了两个类别的产品，则类别对被视为 <strong>可报告的</strong>。</p>
|
||
|
||
<p>返回可报告类别对的结果表以<em> </em><strong>customer_count</strong><em> </em><strong>降序</strong><em> </em>排序，并且为了防止排序持平，以<em> </em><strong>category1 </strong>字典序<strong> 升序</strong> 排序，然后以 <strong>category2 升序</strong> 排序。</p>
|
||
|
||
<p>结果格式如下所示。</p>
|
||
|
||
<p> </p>
|
||
|
||
<p><strong class="example">示例：</strong></p>
|
||
|
||
<div class="example-block">
|
||
<p><strong>输入：</strong></p>
|
||
|
||
<p>ProductPurchases 表：</p>
|
||
|
||
<pre class="example-io">
|
||
+---------+------------+----------+
|
||
| user_id | product_id | quantity |
|
||
+---------+------------+----------+
|
||
| 1 | 101 | 2 |
|
||
| 1 | 102 | 1 |
|
||
| 1 | 201 | 3 |
|
||
| 1 | 301 | 1 |
|
||
| 2 | 101 | 1 |
|
||
| 2 | 102 | 2 |
|
||
| 2 | 103 | 1 |
|
||
| 2 | 201 | 5 |
|
||
| 3 | 101 | 2 |
|
||
| 3 | 103 | 1 |
|
||
| 3 | 301 | 4 |
|
||
| 3 | 401 | 2 |
|
||
| 4 | 101 | 1 |
|
||
| 4 | 201 | 3 |
|
||
| 4 | 301 | 1 |
|
||
| 4 | 401 | 2 |
|
||
| 5 | 102 | 2 |
|
||
| 5 | 103 | 1 |
|
||
| 5 | 201 | 2 |
|
||
| 5 | 202 | 3 |
|
||
+---------+------------+----------+
|
||
</pre>
|
||
|
||
<p>ProductInfo 表：</p>
|
||
|
||
<pre class="example-io">
|
||
+------------+-------------+-------+
|
||
| product_id | category | price |
|
||
+------------+-------------+-------+
|
||
| 101 | Electronics | 100 |
|
||
| 102 | Books | 20 |
|
||
| 103 | Books | 35 |
|
||
| 201 | Clothing | 45 |
|
||
| 202 | Clothing | 60 |
|
||
| 301 | Sports | 75 |
|
||
| 401 | Kitchen | 50 |
|
||
+------------+-------------+-------+
|
||
</pre>
|
||
|
||
<p><strong>输出：</strong></p>
|
||
|
||
<pre class="example-io">
|
||
+-------------+-------------+----------------+
|
||
| category1 | category2 | customer_count |
|
||
+-------------+-------------+----------------+
|
||
| Books | Clothing | 3 |
|
||
| Books | Electronics | 3 |
|
||
| Clothing | Electronics | 3 |
|
||
| Electronics | Sports | 3 |
|
||
+-------------+-------------+----------------+
|
||
</pre>
|
||
|
||
<p><strong>解释：</strong></p>
|
||
|
||
<ul>
|
||
<li><strong>Books-Clothing</strong>:
|
||
|
||
<ul>
|
||
<li>用户 1 购买来自 Books (102) 和 Clothing (201) 的商品</li>
|
||
<li>用户 2 购买来自 Books (102, 103) 和 Clothing (201) 的商品</li>
|
||
<li>用户 5 购买来自 Books (102, 103) 和 Clothing (201, 202) 的商品</li>
|
||
<li>共计：3 个用户购买同一类别的商品</li>
|
||
</ul>
|
||
</li>
|
||
<li><strong>Books-Electronics</strong>:
|
||
<ul>
|
||
<li>用户 1 购买来自 Books (102) 和 Electronics (101) 的商品</li>
|
||
<li>用户 2 购买来自 Books (102, 103) 和 Electronics (101) 的商品</li>
|
||
<li>用户 3 购买来自 Books (103) 和 Electronics (101) 的商品</li>
|
||
<li>共计：3 个消费者购买同一类别的商品</li>
|
||
</ul>
|
||
</li>
|
||
<li><strong>Clothing-Electronics</strong>:
|
||
<ul>
|
||
<li>用户 1 购买来自 Clothing (201) 和 Electronics (101) 的商品</li>
|
||
<li>用户 2 购买来自 Clothing (201) 和 Electronics (101) 的商品</li>
|
||
<li>用户 4 购买来自 Clothing (201) 和 Electronics (101) 的商品</li>
|
||
<li>共计：3 个消费者购买同一类别的商品</li>
|
||
</ul>
|
||
</li>
|
||
<li><strong>Electronics-Sports</strong>:
|
||
<ul>
|
||
<li>用户 1 购买来自 Electronics (101) 和 Sports (301) 的商品</li>
|
||
<li>用户 3 购买来自 Electronics (101) 和 Sports (301) 的商品</li>
|
||
<li>用户 4 购买来自 Electronics (101) 和 Sports (301) 的商品</li>
|
||
<li>共计：3 个消费者购买同一类别的商品</li>
|
||
</ul>
|
||
</li>
|
||
<li>其它类别对比如 Clothing-Sports（只有 2 个消费者：用户 1 和 4）和 Books-Kitchen（只有 1 个消费者：用户 3）共同的消费者少于 3 个，因此不包含在结果内。</li>
|
||
</ul>
|
||
|
||
<p>结果按 customer_count 降序排列。由于所有对都有相同的客户数量 3，它们按 category1（然后是 category2）升序排列。</p>
|
||
</div>
|