Medium data structure and algorithm practice puzzle.
Given an array of numbers, return the largest sum of any contiguous run. Walk through once with a running total. At each number, decide: is this number better on its own, or added to the run so far? A run that's gone negative only drags things down, so starting fresh wins. Keep the best total you see. That's Kadane's algorithm.
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 Track Streak Finder, a pipeline you can run and download. See every Software Engineer project.
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