Easy data structure and algorithm practice puzzle.
Given a sorted linked list, passed in as its values, remove the duplicates so each value appears once. Because the list is sorted, duplicates always sit next to each other. Walk the list once and only keep a value if it's different from the last one you kept. No set needed.
Solve it three ways: snap the jigsaw pieces together, fill in the blanks, or type it from scratch against the tests. This one is free.
Every line of the solution comes with a note explaining why it is there, and a step by step replay shows the code running. At level 3, where you type it yourself, you can ask for an AI mock interview on this problem that ends with a hiring manager's scorecard.
Then grow it into a real project with the Software Engineer button: this puzzle becomes the Ticket Cache Tier, a pipeline you can run and download. See every Software Engineer project.
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