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61 lines
2.3 KiB
HTML
61 lines
2.3 KiB
HTML
<p>Table: <code>Users</code></p>
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<pre>
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+---------------+---------+
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| Column Name | Type |
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+---------------+---------+
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| user_id | int |
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| name | varchar |
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| mail | varchar |
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+---------------+---------+
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user_id is the primary key (column with unique values) for this table.
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This table contains information of the users signed up in a website. Some e-mails are invalid.
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</pre>
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<p> </p>
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<p>Write a solution to find the users who have <strong>valid emails</strong>.</p>
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<p>A valid e-mail has a prefix name and a domain where:</p>
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<ul>
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<li><strong>The prefix name</strong> is a string that may contain letters (upper or lower case), digits, underscore <code>'_'</code>, period <code>'.'</code>, and/or dash <code>'-'</code>. The prefix name <strong>must</strong> start with a letter.</li>
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<li><strong>The domain</strong> is <code>'@leetcode.com'</code>.</li>
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</ul>
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<p>Return the result table in <strong>any order</strong>.</p>
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<p>The result format is in the following example.</p>
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<p> </p>
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<p><strong class="example">Example 1:</strong></p>
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<pre>
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<strong>Input:</strong>
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Users table:
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+---------+-----------+-------------------------+
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| user_id | name | mail |
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+---------+-----------+-------------------------+
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| 1 | Winston | winston@leetcode.com |
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| 2 | Jonathan | jonathanisgreat |
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| 3 | Annabelle | bella-@leetcode.com |
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| 4 | Sally | sally.come@leetcode.com |
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| 5 | Marwan | quarz#2020@leetcode.com |
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| 6 | David | david69@gmail.com |
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| 7 | Shapiro | .shapo@leetcode.com |
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+---------+-----------+-------------------------+
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<strong>Output:</strong>
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+---------+-----------+-------------------------+
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| user_id | name | mail |
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+---------+-----------+-------------------------+
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| 1 | Winston | winston@leetcode.com |
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| 3 | Annabelle | bella-@leetcode.com |
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| 4 | Sally | sally.come@leetcode.com |
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+---------+-----------+-------------------------+
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<strong>Explanation:</strong>
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The mail of user 2 does not have a domain.
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The mail of user 5 has the # sign which is not allowed.
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The mail of user 6 does not have the leetcode domain.
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The mail of user 7 starts with a period.
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</pre>
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