题目:Merge k sorted linked lists and return it as one sorted list. Analyze and describe its complexity. 解析:合并k个已经有序的单链表,使其最终成为一个有序的单链表.原理就是归并排序,递归运算.基本算法recusion 与 merge 编码: public ListNode mergeKLists(ListNode[] lists) { if(lists == null || lists.leng…
package cookie; public class MergeSort { void mergeSort(int[] a, int[] temp, int left, int right) { if (left < right) { int center = (left + right) / 2; mergeSort(a, temp, left, center); mergeSort(a, temp, center + 1, right); merge(a, temp, left, cen…
import java.util.Scanner; public class Main { private static int count=0; public static void mergesort(int a[],int low,int high) { if(low<high) { int mid=(low+high)>>1; mergesort(a,low,mid); mergesort(a,mid+1,high); merge(a,low,mid,high); } } pri…
本文描述了LeetCode 148题 sort-list 的解法. 题目描述如下: Sort a linked list in O(n log n) time using constant space complexity. 题目要求我们在O(n log n)时间复杂度下完成对单链表的排序,我们知道平均时间复杂度为O(n log n)的排序方法有快速排序.归并排序和堆排序.而一般是用数组来实现二叉堆,当然可以用二叉树来实现,但是这么做太麻烦,还得花费额外的空间构建二叉树,于是不采用堆排序. 故本…