How the Fast Fourier Transform Multiplies Polynomials
Reducible · Explainer · YouTube title: The Fast Fourier Transform (FFT): Most Ingenious Algorithm Ever?
Why it's here
HN repeatedly calls it a fantastic explanation that made FFT click, with some rewatching it periodically.
What it covers
Reducible's visual walkthrough of the Fast Fourier Transform, motivated by polynomial multiplication. It shows how the FFT's key ideas can be discovered by asking the right questions.