Add problem 2016: Maximum Difference Between Increasing Elements

src/lib.rs

@@ -1393,6 +1393,7 @@ pub mod problem_2006_count_number_of_pairs_with_absolute_difference_k;
 pub mod problem_2007_find_original_array_from_doubled_array;
 pub mod problem_2011_final_value_of_variable_after_performing_operations;
 pub mod problem_2012_sum_of_beauty_in_the_array;
+pub mod problem_2016_maximum_difference_between_increasing_elements;
 
 #[cfg(test)]
 mod test_utilities;

src/problem_2016_maximum_difference_between_increasing_elements/iterative.rs

@@ -0,0 +1,36 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn maximum_difference(nums: Vec<i32>) -> i32 {
+        let mut result = -1;
+        let mut min = i32::MAX;
+
+        for num in nums {
+            min = min.min(num);
+
+            if num > min {
+                result = result.max(num - min);
+            }
+        }
+
+        result
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn maximum_difference(nums: Vec<i32>) -> i32 {
+        Self::maximum_difference(nums)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2016_maximum_difference_between_increasing_elements/mod.rs

@@ -0,0 +1,18 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn maximum_difference(nums: Vec<i32>) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [(&[7, 1, 5, 4] as &[_], 4), (&[9, 4, 3, 2], -1), (&[1, 5, 2, 10], 9)];
+
+        for (nums, expected) in test_cases {
+            assert_eq!(S::maximum_difference(nums.to_vec()), expected);
+        }
+    }
+}