add 2181

Author: fishercoder1534

README.md

@@ -8,6 +8,7 @@ _If you like this project, please leave me a star._ ★
 
 | #    |      Title     |   Solutions   | Video  | Difficulty  | Tag                  
 |------|----------------|---------------|--------|-------------|-------------
+| 2181 |[Merge Nodes in Between Zeros](https://leetcode.com/problems/merge-nodes-in-between-zeros/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2181.java) ||Medium||
 | 2180 |[Count Integers With Even Digit Sum](https://leetcode.com/problems/count-integers-with-even-digit-sum/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2180.java) ||Easy||
 | 2177 |[Find Three Consecutive Integers That Sum to a Given Number](https://leetcode.com/problems/find-three-consecutive-integers-that-sum-to-a-given-number/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2177.java) ||Medium||
 | 2176 |[Count Equal and Divisible Pairs in an Array](https://leetcode.com/problems/count-equal-and-divisible-pairs-in-an-array/)|[Java](../master/src/main/java/com/fishercoder/solutions/_2176.java) ||Easy||

src/main/java/com/fishercoder/solutions/_2181.java

@@ -0,0 +1,30 @@
+package com.fishercoder.solutions;
+
+import com.fishercoder.common.classes.ListNode;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class _2181 {
+    public static class Solution1 {
+        public ListNode mergeNodes(ListNode head) {
+            List<Integer> list = new ArrayList<>();
+            while (head != null) {
+                list.add(head.val);
+                head = head.next;
+            }
+            ListNode pre = new ListNode(-1);
+            ListNode tmp = pre;
+            for (int i = 1; i < list.size(); i++) {
+                int sum = 0;
+                while (i < list.size() && list.get(i) != 0) {
+                    sum += list.get(i);
+                    i++;
+                }
+                tmp.next = new ListNode(sum);
+                tmp = tmp.next;
+            }
+            return pre.next;
+        }
+    }
+}