Add problem 2181: Merge Nodes in Between Zeros

src/lib.rs

@@ -1549,6 +1549,7 @@ pub mod problem_2169_count_operations_to_obtain_zero;
 pub mod problem_2170_minimum_operations_to_make_the_array_alternating;
 pub mod problem_2177_find_three_consecutive_integers_that_sum_to_a_given_number;
 pub mod problem_2180_count_integers_with_even_digit_sum;
+pub mod problem_2181_merge_nodes_in_between_zeros;
 pub mod problem_2185_counting_words_with_a_given_prefix;
 pub mod problem_2186_minimum_number_of_steps_to_make_two_strings_anagram_ii;
 pub mod problem_2190_most_frequent_number_following_key_in_an_array;

src/problem_2181_merge_nodes_in_between_zeros/iterative.rs

@@ -0,0 +1,49 @@
+use crate::data_structures::ListNode;
+
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn merge_nodes(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        let mut result = None;
+        let mut tail = &mut result;
+        let mut iter = head;
+
+        while let Some(mut node) = iter {
+            let mut sum = node.val;
+
+            loop {
+                node = node.next.unwrap();
+
+                if node.val == 0 {
+                    iter = node.next.take();
+                    node.val = sum;
+                    tail = &mut tail.insert(node).next;
+
+                    break;
+                }
+
+                sum += node.val;
+            }
+        }
+
+        result
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn merge_nodes(head: Option<Box<ListNode>>) -> Option<Box<ListNode>> {
+        Self::merge_nodes(head)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}

src/problem_2181_merge_nodes_in_between_zeros/mod.rs

@@ -0,0 +1,29 @@
+use crate::data_structures::ListNode;
+
+pub mod iterative;
+
+pub trait Solution {
+    fn merge_nodes(head: Option<Box<ListNode>>) -> Option<Box<ListNode>>;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+    use crate::test_utilities;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (&[0, 3, 1, 0, 4, 5, 2, 0], &[4, 11] as &[_]),
+            (&[0, 1, 0, 3, 0, 2, 2, 0], &[1, 3, 4]),
+        ];
+
+        for (head, expected) in test_cases {
+            assert_eq!(
+                &test_utilities::iter_list(&S::merge_nodes(test_utilities::make_list(head.iter().copied())))
+                    .copied()
+                    .collect::<Vec<_>>(),
+                expected,
+            );
+        }
+    }
+}