public class Solution
extends Object
2181 - Merge Nodes in Between Zeros\.
Medium
You are given the `head` of a linked list, which contains a series of integers **separated** by `0`'s. The **beginning** and **end** of the linked list will have `Node.val == 0`.
For **every** two consecutive `0`'s, **merge** all the nodes lying in between them into a single node whose value is the **sum** of all the merged nodes. The modified list should not contain any `0`'s.
Return _the_ `head` _of the modified linked list_.
**Example 1:**
**Input:** head = [0,3,1,0,4,5,2,0]
**Output:** [4,11]
**Explanation:**
The above figure represents the given linked list. The modified list contains
- The sum of the nodes marked in green: 3 + 1 = 4.
- The sum of the nodes marked in red: 4 + 5 + 2 = 11.
**Example 2:**
**Input:** head = [0,1,0,3,0,2,2,0]
**Output:** [1,3,4]
**Explanation:**
The above figure represents the given linked list. The modified list contains
- The sum of the nodes marked in green: 1 = 1.
- The sum of the nodes marked in red: 3 = 3.
- The sum of the nodes marked in yellow: 2 + 2 = 4.
**Constraints:**
* The number of nodes in the list is in the range [3, 2 * 105].
* `0 <= Node.val <= 1000`
* There are **no** two consecutive nodes with `Node.val == 0`.
* The **beginning** and **end** of the linked list have `Node.val == 0`.