Learn how to solve the Leetcode problem of id 290, whose title is Word Pattern, using the Java programming language.

https://leetcode.com/problems/word-pattern

The Data Structures and Algorithms (DSA) lesson uses an iterative approach with a hash map.

Take the string s and split it into an array of strings, each element being a word.

Traverse each character of the string pattern. Look at the specific character and check the hash map to see if it has not already been seen.

Take an approach where you are looking for some flaw in the loop. If a flaw is found, return false right away. Otherwise, if the loop completes without finding any flaws, you can take the answer to be a valid pattern matching.

The key for the hash map is the character pattern, a letter such as a or b.

The value for the hash map is the word associated with the letter. For example, dog.

A set is also used to keep track of words already seen, to handle a special case.

The time complexity for the solution is O(n) and its space complexity is O(n).

DSA problems are sometimes asked during tech job interviews for positions such as Software Engineer, so you can use the challenge to practice that skill.