Codex/find and fix a bug (#12782)

* Fix enumeration order in FFT string representation

* updating DIRECTORY.md

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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* Update radix2_fft.py

* [pre-commit.ci] auto fixes from pre-commit.com hooks

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Co-authored-by: alejandroaldas <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: Maxim Smolskiy <[email protected]>