Add problem 3196: Maximize Total Cost of Alternating Subarrays

Author: EFanZh

src/lib.rs

@@ -2132,6 +2132,7 @@ pub mod problem_3191_minimum_operations_to_make_binary_array_elements_equal_to_o
 pub mod problem_3192_minimum_operations_to_make_binary_array_elements_equal_to_one_ii;
 pub mod problem_3194_minimum_average_of_smallest_and_largest_elements;
 pub mod problem_3195_find_the_minimum_area_to_cover_all_ones_i;
+pub mod problem_3196_maximize_total_cost_of_alternating_subarrays;
 pub mod problem_3350_adjacent_increasing_subarrays_detection_ii;
 
 #[cfg(test)]

src/problem_3196_maximize_total_cost_of_alternating_subarrays/dynamic_programming.rs

@@ -0,0 +1,36 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn maximum_total_cost(nums: Vec<i32>) -> i64 {
+        let mut even_cost = 0;
+        let mut odd_cost = i64::MIN / 2;
+
+        for num in nums {
+            let num = i64::from(num);
+            let new_odd_cost = even_cost.max(odd_cost) + num;
+            let new_even_cost = new_odd_cost.max(odd_cost - num);
+
+            (even_cost, odd_cost) = (new_even_cost, new_odd_cost);
+        }
+
+        even_cost.max(odd_cost)
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn maximum_total_cost(nums: Vec<i32>) -> i64 {
+        Self::maximum_total_cost(nums)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_3196_maximize_total_cost_of_alternating_subarrays/mod.rs

@@ -0,0 +1,23 @@
+pub mod dynamic_programming;
+
+pub trait Solution {
+    fn maximum_total_cost(nums: Vec<i32>) -> i64;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (&[1, -2, 3, 4] as &[_], 10),
+            (&[1, -1, 1, -1], 4),
+            (&[0], 0),
+            (&[-937], -937),
+        ];
+
+        for (nums, expected) in test_cases {
+            assert_eq!(S::maximum_total_cost(nums.to_vec()), expected);
+        }
+    }
+}