Medium data structure and algorithm practice puzzle.
Given two strings, return true if you can turn one into the other by swapping each letter for another letter, the same way every time. So "egg" and "add" work, and "foo" and "bar" don't. You need TWO maps, one each direction. With only one, "ab" could map onto "aa", because nothing stops two letters from turning into the same one.
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 Trip Deduplicator, a pipeline you can run and download. See every Software Engineer project.
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