Medium data structure and algorithm practice puzzle.
Given t from 0 to 1, return 6t^5 - 15t^4 + 10t^3, rounded to 4 decimals. Write it nested to save multiplies: t x t x t x (t x (t x 6 - 15) + 10). This smooth curve is what Ken Perlin swapped into his noise in 2002, because it flattens out completely at both ends and hides the grid lines.
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 Frame Replay Log, a pipeline you can run and download. See every Software Engineer project.
Browse all 576 puzzles