problem23

README

< Previous 　　　　　　　　　　　　　　　　 Next >

23. Merge k Sorted Lists (Hard)

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

Merge all the linked-lists into one sorted linked-list and return it.

 

Example 1:

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

Example 2:

Input: lists = []
Output: []

Example 3:

Input: lists = [[]]
Output: []

 

Constraints:

• k == lists.length
• 0 <= k <= 10^4
• 0 <= lists[i].length <= 500
• -10^4 <= lists[i][j] <= 10^4
• lists[i] is sorted in ascending order.
• The sum of lists[i].length won't exceed 10^4.

Related Topics

[Heap] [Linked List] [Divide and Conquer]

Similar Questions

1. Merge Two Sorted Lists (Easy)
2. Ugly Number II (Medium)

Documentation

Index

• type ListNode

Types

type ListNode

type ListNode = kit.ListNode

ListNode - Definition for singly-linked list.