diff options
| author | mzuenni <mzuenni@users.noreply.github.com> | 2024-07-28 22:54:40 +0200 |
|---|---|---|
| committer | GitHub <noreply@github.com> | 2024-07-28 22:54:40 +0200 |
| commit | 8d11c6c8213f46f0fa19826917c255edd5d43cb1 (patch) | |
| tree | 96d75baff33d5a04b5a60f1a41f514a26c716874 /content/math/transforms/fft.cpp | |
| parent | 8c33b4e0d3030cfed17fc64b4fe41133339f6d87 (diff) | |
Test (#4)
* update
* moved content in subdir
* rename file
* add test setup
* add test setup
* add github action
* automaticly test all cpp files
* timeout after 10s
* setulimit and dont zero memory
* test build pdf
* install latexmk
* update
* update
* ngerman
* fonts
* removed old code
* add first test
* added tests
* test in sorted order
* more tests
* simplified test
* more tests
* fix suffix tree
* fixes and improvements
* done ust lst directly
* fix swap
* add links to pdf
* fix constants
* add primorial
* add comment
* various improvements
* more tests
* added missing stuf
* more tests
* fix tests
* more tests
* more tests
* more tests
* fix recursion?
* test trie
* more tests
* only use python temporarily for listings
* only use python temporarily for listings
* more tests
* fix longestCommonSubstring
* more tests
* more tests
* made code more similiar
* fix?
* more tests
* more tests
* more tests
* add ahoCorasick test + limit 4GB stack size
* more tests
* fix test
* add additional test
* more tests
* more tests
* fix?
* better fix
* fix virtual tree
* more tests
* more tests
* recursive closest pair
* more tests
* decrease limit
* new tests
* more tests
* fix name
* more tests
* add test
* new test
* more tests
* more tests
* more tests
* more tests
* new test and content
* new code
* new code
* larger tests
* fix and test
* new test
* new test
* update pdf
* remove comments
* new test
* more tests
* more testcases
* more tests
* increased limit
* more tests
* more tests
* more tests
* new tests
* more tests
* shortened code
* new test
* add basic tests for bigint
* more tests
* removed old files
* new test
* ignore some files
* more auto more ccw
* fix test
* more tests
* fix
* new tests
* more tests
* more tests
* stronger test
* actually verify delaunay...
* more tests
* fix header
* more tests
* run tests parallel?
* test parralel?
* add --missing
* separate workflows
* test
* is the pdf checked?
* separate workflows
* fix workflow
* more workflows
---------
Co-authored-by: Yidi <noob999noob999@gmail.com>
Diffstat (limited to 'content/math/transforms/fft.cpp')
| -rw-r--r-- | content/math/transforms/fft.cpp | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/content/math/transforms/fft.cpp b/content/math/transforms/fft.cpp new file mode 100644 index 0000000..2bd95b2 --- /dev/null +++ b/content/math/transforms/fft.cpp @@ -0,0 +1,23 @@ +using cplx = complex<double>; + +void fft(vector<cplx>& a, bool inv = false) { + int n = sz(a); + for (int i = 0, j = 1; j < n - 1; ++j) { + for (int k = n >> 1; k > (i ^= k); k >>= 1); + if (j < i) swap(a[i], a[j]); + } + static vector<cplx> ws(2, 1); + for (static int k = 2; k < n; k *= 2) { + ws.resize(n); + cplx w = polar(1.0, acos(-1.0) / k); + for (int i=k; i<2*k; i++) ws[i] = ws[i/2] * (i % 2 ? w : 1); + } + for (int s = 1; s < n; s *= 2) { + for (int j = 0; j < n; j += 2 * s) { + for (int k = 0; k < s; k++) { + cplx u = a[j + k], t = a[j + s + k]; + t *= (inv ? conj(ws[s + k]) : ws[s + k]); + a[j + k] = u + t; + a[j + s + k] = u - t; + if (inv) a[j + k] /= 2, a[j + s + k] /= 2; +}}}} |