同一数组中每个元素的数据类型（int long short double float char...）必须相同。

Given a pattern and a string str, find if str follows the same pattern.

Write a bash script to calculate the frequency of each word in a text file words.txt.

Write a SQL query to find all duplicate emails in a table named Person.

Implement a trie with insert, search, and startsWith methods.

Design a data structure that supports the following two operations:

Given a pattern and a string str, find if str follows the same pattern.

Peter likes to travel by train. He likes it so much that on the train he falls asleep.

Implement a trie with insert, search, and startsWith methods.

211. Add and Search Word - Data structure design Design a data structure that supports the following two operations: