Add solution #929

Author: JoshCrozier

solutions/0929-unique-email-addresses.js

@@ -0,0 +1,33 @@
+/**
+ * 929. Unique Email Addresses
+ * https://leetcode.com/problems/unique-email-addresses/
+ * Difficulty: Easy
+ *
+ * Every email consists of a local name and a domain name, separated by the @ sign.
+ *
+ * For example, in [email protected], alice is the local name, and leetcode.com is the domain name.
+ *
+ * Besides lowercase letters, these emails may contain '.'s or '+'s.
+ *
+ * If you add periods ('.') between some characters in the local name part of an email address, mail
+ * sent there will be forwarded to the same address without dots in the local name.
+ * For example, "[email protected]" and "[email protected]" forward to the same email address.
+ * (Note that this rule does not apply for domain names.)
+ *
+ * If you add a plus ('+') in the local name, everything after the first plus sign will be ignored.
+ * This allows certain emails to be filtered, for example [email protected] will be forwarded to
+ * [email protected]. (Again, this rule does not apply for domain names.)
+ *
+ * It is possible to use both of these rules at the same time.
+ *
+ * Given a list of emails, we send one email to each address in the list.
+ * How many different addresses actually receive mails?
+ */
+
+/**
+ * @param {string[]} emails
+ * @return {number}
+ */
+var numUniqueEmails = function(emails) {
+  return new Set(emails.map(e => e.replace(/\.(?=[\w\.+]+@)|\+[\w.+]+(?=@)/g, ''))).size;
+};