From f4dafa64e27e63d8cde5adcfbfa98e2a30fb7504 Mon Sep 17 00:00:00 2001
From: Noobie99 <noob999noob999@gmail.com>
Date: Mon, 5 Feb 2024 22:23:53 +0100
Subject: renamed ntt and bitwiseConv function + more multiply functions

---
 math/transforms/multiplyFFT.cpp | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 math/transforms/multiplyFFT.cpp

(limited to 'math/transforms/multiplyFFT.cpp')

diff --git a/math/transforms/multiplyFFT.cpp b/math/transforms/multiplyFFT.cpp
new file mode 100644
index 0000000..0022d1f
--- /dev/null
+++ b/math/transforms/multiplyFFT.cpp
@@ -0,0 +1,12 @@
+vector<ll> mul(vector<ll>& a, vector<ll>& b) {
+	int n = 1 << (__lg(sz(a) + sz(b) - 1) + 1);
+	vector<cplx> a2(all(a)), b2(all(b));
+	a2.resize(n), b2.resize(n);
+	fft(a2), fft(b2);
+	for (int i=0; i<n; i++) a2[i] *= b2[i];
+	fft(a2, true);
+
+	vector<ll> ans(n);
+	for (int i=0; i<n; i++) ans[i] = llround(a2[i].real());
+	return ans;
+}
-- 
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