Added function to get factorial of number

src/Algorithms.rs

@@ -478,4 +478,13 @@ pub fn gcd(in1: i32, in2: i32) -> i32{
 		}
 	}
 	return num1 | num2;
+}
+
+//Returns the factorial of the number passed in
+pub fn factorial(num: i64) -> i64{
+	let mut fact = 1;
+	for cnt in 1 ..= num{
+		fact *= cnt;
+	}
+	return fact;
 }