likecool21的专栏

You are given two linked lists representing two non-negative numbers. The digits are stored in reverse order and each of their nodes contain a single digit. Add the two numbers and return it as a link

Sort a linked list in O(n log n) time using constant space complexity.挺有意思的题，这里用了merge sort，可以利用到merge sorted list 那题的代码/** * Definition for singly-linked list. * class ListNode { *

Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.For example,Given 1->2->3->3->4->4->5, return 1->2->5.Given 1->

Reverse a linked list from position m to n. Do it in-place and in one-pass.For example:Given 1->2->3->4->5->NULL, m = 2 and n = 4,return 1->4->3->2->5->NULL.Note:Given m, n satisfy t

Given a linked list, return the node where the cycle begins. If there is no cycle, return null.Follow up:Can you solve it without using extra space?

Given a linked list, swap every two adjacent nodes and return its head.For example,Given 1->2->3->4, you should return the list as 2->1->4->3.Your algorithm should use only constant space. Y

Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists.这题不能像merge

Given a linked list, remove the nth node from the end of list and return its head.For example, Given linked list: 1->2->3->4->5, and n = 2. After removing the second node from the end, the

Given a list, rotate the list to the right by k places, where k is non-negative.For example:Given 1->2->3->4->5->NULL and k = 2,return 4->5->1->2->3->NULL.这题xiang

Given a singly linked list L: L0→L1→…→Ln-1→Ln,reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→…You must do this in-place without altering the nodes' values.For example,Given {1,2,3,4}, reorder it to 

Given a sorted linked list, delete all duplicates such that each element appear only once.For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3, return 1->2->3.先写了一个用extra space的方法，

在stackoverflow上看到一个好的方案。http://stackoverflow.com/questions/354875/reversing-a-linked-list-in-java-recursivelyThree questions to ask:What is the reverse of null (the empty list)? null.What

Given a linked list and a value x, partition it such that all nodes less than x come before nodes greater than or equal to x.You should preserve the original relative order of the nodes in each of