Avoid large intermediate product in LCM

mhogrefe · mhogrefe · commit 56a029b20f0e · 2017-12-13T21:13:57.000-05:00
diff --git a/bigint/src/biguint.rs b/bigint/src/biguint.rs
@@ -955,7 +955,7 @@ impl Integer for BigUint {
     /// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
     #[inline]
     fn lcm(&self, other: &BigUint) -> BigUint {
-        ((self * other) / self.gcd(other))
+        self / self.gcd(other) * other
     }
 
     /// Deprecated, use `is_multiple_of` instead.

Original file line number	Diff line number	Diff line change
`@@ -955,7 +955,7 @@ impl Integer for BigUint {`
`955`	`955`	/// Calculates the Lowest Common Multiple (LCM) of the number and `other`.
`956`	`956`	`#[inline]`
`957`	`957`	`fn lcm(&self, other: &BigUint) -> BigUint {`
`958`		`- ((self * other) / self.gcd(other))`
	`958`	`+ self / self.gcd(other) * other`
`959`	`959`	`}`
`960`	`960`
`961`	`961`	/// Deprecated, use `is_multiple_of` instead.