About

One Hint Away teaches data structures and algorithms one pattern at a time, on Instagram at @onehintaway.

Two kinds of post

• Pattern posts teach one idea: how to spot it in a problem, a dry run on a tiny input, the trap, and the code.
• Challenge posts take one hard problem and give hints one at a time, so you can stop as soon as you see the answer.

What this site adds

• The slides, including the animated ones.
• Tested code in Java, Python, C++ and JavaScript, with a copy button. The site remembers your language.
• Practice problems you can click straight through to.

New here? Read Start here, then follow the posts in order on the home page, or jump to one in the patterns index.