# Leetcode Merge k Sorted Lists problem solution in Java In the Leetcode Merge k Sorted Lists problem solution in Java programming Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.

You are given an array of k linked-lists lists, each linked-list is sorted in ascending order.

Example 1:

Input: lists = [[1,4,5],[1,3,4],[2,6]]
Output: [1,1,2,3,4,4,5,6]
[
1->4->5,
1->3->4,
2->6
]
merging them into one sorted list:
1->1->2->3->4->4->5->6

Constraints:

• k == lists.length
• 0 <= k <= 104
• 0 <= lists[i].length <= 500
• -104 <= lists[i][j] <= 104
• lists[i] is sorted in ascending order.
• The sum of lists[i].length will not exceed 104.

## Leetcode Merge k Sorted Lists problem solution in Java programming

``````class Solution {
public ListNode mergeKLists(ListNode[] lists) {
if (lists == null || lists.length == 0) {
return null;
}
PriorityQueue<Integer> queue = new PriorityQueue<>();
for (ListNode node : lists) {
while (node != null) {
queue.offer(node.val);
node = node.next;
}
}
return getNode(queue);

}
private  ListNode getNode(PriorityQueue<Integer> queue) {
if (!queue.isEmpty()) {
ListNode node = new ListNode(queue.poll(), null);
node.next = getNode(queue);
return node;
}
return null;
}
}`````` #### By Neha Singhal

Hi, my name is Neha singhal a software engineer and coder by profession. I like to solve coding problems that give me the power to write posts for this site.