From 0257f0b3c61f203f64c3817dfe19a08f6191517c Mon Sep 17 00:00:00 2001
From: mzuenni <michi.zuendorf@gmail.com>
Date: Wed, 11 Sep 2024 00:29:27 +0200
Subject: moved stuff

---
 content/math/recover.cpp | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 content/math/recover.cpp

(limited to 'content/math/recover.cpp')

diff --git a/content/math/recover.cpp b/content/math/recover.cpp
new file mode 100644
index 0000000..1a593f0
--- /dev/null
+++ b/content/math/recover.cpp
@@ -0,0 +1,13 @@
+ll sq(ll x) {return x*x;}
+
+array<ll, 2> recover(ll c, ll m) {
+	array<ll, 2> u = {m, 0}, v = {c, 1};
+	while (m <= 2 * sq(v[0])) {
+		ll q = u[0] / v[0];
+		u[0] -= q * v[0];
+		u[1] -= q * v[1];
+		swap(u, v);
+	}
+	if (v[1] <= 0 || 2 * sq(v[1]) >= m) return {-1, -1};
+	return v;
+}
-- 
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