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authormzuenni <michi.zuendorf@gmail.com>2022-06-27 17:19:28 +0200
committermzuenni <michi.zuendorf@gmail.com>2022-06-27 17:19:28 +0200
commit5ab8a5088b729a9953b8dff1b2a985dc8fb2098b (patch)
treeed40d6936c0e9eee40ba62751cbf99ecddbaddc2 /math/transforms/orTransform.cpp
parentadabbad9c51cf7cd3874bfde8eac1fbcf84fec10 (diff)
updated tcr
Diffstat (limited to 'math/transforms/orTransform.cpp')
-rw-r--r--math/transforms/orTransform.cpp17
1 files changed, 17 insertions, 0 deletions
diff --git a/math/transforms/orTransform.cpp b/math/transforms/orTransform.cpp
new file mode 100644
index 0000000..fdb5bb8
--- /dev/null
+++ b/math/transforms/orTransform.cpp
@@ -0,0 +1,17 @@
+void fft(vector<ll>& a, bool inverse = 0) {
+ 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]);
+ }
+ for (int s = 1; s < n; s *= 2) {
+ for (int j = 0; j < n; j+= 2 * s) {
+ for (int k = 0; k < s; k++) {
+ ll u = a[j + k], t = a[j + s + k];
+ if (!inverse) {
+ a[j + k] = u + t;
+ a[j + s + k] = u;
+ } else {
+ a[j + k] = t;
+ a[j + s + k] = u - t;
+}}}}}