added spqlios as submodule

rns/src/num_bigint.rs

@@ -0,0 +1,31 @@
+use num_bigint::BigInt;
+use num_integer::Integer;
+use num_traits::{One, Signed, Zero};
+
+pub trait Div {
+    fn div_floor(&self, other: &Self) -> Self;
+    fn div_round(&self, other: &Self) -> Self;
+}
+
+impl Div for BigInt {
+    fn div_floor(&self, other: &Self) -> Self {
+        let quo: BigInt = self / other;
+        if self.sign() != other.sign() {
+            return quo - BigInt::one();
+        }
+        return quo;
+    }
+
+    fn div_round(&self, other: &Self) -> Self {
+        let (quo, mut rem) = self.div_rem(other);
+        rem <<= 1;
+        if rem != BigInt::zero() && &rem.abs() > other {
+            if self.sign() == other.sign() {
+                return quo + BigInt::one();
+            } else {
+                return quo - BigInt::one();
+            }
+        }
+        return quo;
+    }
+}