[pull] master from TheAlgorithms:master

src/math/abs.rs

@@ -0,0 +1,30 @@
+/// This function returns the absolute value of a number.
+/// The absolute value of a number is the non-negative value of the number, regardless of its sign
+/// Wikipedia: https://en.wikipedia.org/wiki/Absolute_value
+pub fn abs(num: f64) -> f64 {
+    if num < 0.0 {
+        return -num;
+    }
+
+    num
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn negative_number() {
+        assert_eq!(420.0, abs(-420.0));
+    }
+
+    #[test]
+    fn zero() {
+        assert_eq!(0.0, abs(0.0));
+    }
+
+    #[test]
+    fn positive_number() {
+        assert_eq!(69.69, abs(69.69));
+    }
+}

src/math/mod.rs

@@ -1,3 +1,4 @@
+mod abs;
 mod aliquot_sum;
 mod amicable_numbers;
 mod armstrong_number;
@@ -39,6 +40,7 @@ mod square_root;
 mod trial_division;
 mod zellers_congruence_algorithm;
 
+pub use self::abs::abs;
 pub use self::aliquot_sum::aliquot_sum;
 pub use self::amicable_numbers::amicable_pairs_under_n;
 pub use self::armstrong_number::is_armstrong_number;