23. Merge k Sorted Lists

Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity.

Example:

Input:[  1->4->5,  1->3->4,  2->6]Output: 1->1->2->3->4->4->5->6 题意：按大小顺序合并n条链表 代码如下：

/** * Definition for singly-linked list. * function ListNode(val) { *     this.val = val; *     this.next = null; * } *//** * @param {ListNode[]} lists * @return {ListNode} */var mergeKLists = function(lists) {    if(lists.length===0) return null;    var n=lists.length;    while(n>1){        var k=parseInt((n+1)/2);        for(var i=0;i