Revert "Fix division"

Actually you cannot do division like that, the result is not unique.

This reverts commit 771667c2bb52235d6dacf67eab933207b59e167b.

2 files changed, 3 insertions, 15 deletions

diff --git a/test b/test
index d80dc2b..4b426c2 100755
--- a/test
+++ b/test
@@ -141,16 +141,6 @@ public:
                 assert_equal(p, 92);
         }
 },
-{
-        .name = "4 / 2 mod 6",
-        .f = []() {
-                Zmod<6> four = 4;
-                Zmod<6> two = 2;
-                auto d = four / two;
-                assert_equal(d.has_value(), true);
-                assert_equal(d.value(), 2);
-        }
-},
 };
 
 int main() {
diff --git a/zmodn.h b/zmodn.h
index 890fb0e..fdb1ee6 100644
--- a/zmodn.h
+++ b/zmodn.h
@@ -40,15 +40,13 @@ public:
         bool operator!=(const Zmod& z) const { return value != z.value; }
 
         std::optional<Zmod> inverse() const {
-                auto [g, a, b] = extended_gcd(value, N);
+                auto [g, a, _] = extended_gcd(value, N);
                 return g == 1 ? Zmod(a) : std::optional<Zmod>{};
         }
 
         std::optional<Zmod> operator/(const Zmod& d) const {
-                auto [g, x, y] = extended_gcd(value, d.toint());
-                auto [a, b] = std::pair<Zmod, Zmod>{value / g, d.toint() / g};
-                auto i = b.inverse();
-                return i ? a * i.value() : i;
+                auto i = d.inverse();
+                return i ? (*this) * i.value() : i;
         }
 
         std::optional<Zmod> operator/=(const Zmod& d) {