Count how many nodes in a linked list. Example Given 1->3->5, return 3. 解法一: /** * Definition of ListNode * class ListNode { * public: * int val; * ListNode *next; * ListNode(int val) { * this->val = val; * this->next = NULL; * } * } */ class…

Remove all elements from a linked list of integers that have value val. Example Given 1->2->3->3->4->5->3, val = 3, you should return the list as 1->2->4->5 解法一: /** * Definition for singly-linked list. * struct ListNode { * int…

92. Reverse Linked List II[Medium] 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 the fo…

203. Remove Linked List Elements[easy] Remove all elements from a linked list of integers that have value val. ExampleGiven: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6Return: 1 --> 2 --> 3 --> 4 --> 5 Credits:Special than…

141. Linked List Cycle[easy] Given a linked list, determine if it has a cycle in it. Follow up:Can you solve it without using extra space? 解法一: /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x…

Remove all elements from a linked list of integers that have value val. Example: Input: 1->2->6->3->4->5->6, val = 6 Output: 1->2->3->4->5 /** * Definition for singly-linked list. * public class ListNode { * int val; * ListNo…

Insert a node in a sorted linked list. Example Given list = 1->4->6->8 and val = 5. Return 1->4->5->6->8. 解法一: /** * Definition of ListNode * class ListNode { * public: * int val; * ListNode *next; * ListNode(int val) { * this->val…

Given a linked list, determine if it has a cycle in it.   Example Given -21->10->4->5, tail connects to node index 1, return true Challenge Follow up:Can you solve it without using extra space? 解法一: class Solution { public: /** * @param head: The…

Given a linked list, determine if it has a cycle in it. To represent a cycle in the given linked list, we use an integer pos which represents the position (0-indexed) in the linked list where tail connects to. If pos is -1, then there is no cycle in…

Find the Nth number in Fibonacci sequence. A Fibonacci sequence is defined as follow: The first two numbers are 0 and 1. The i th number is the sum of i-1 th number and i-2 th number. The first ten numbers in Fibonacci sequence is: 0, 1, 1, 2, 3, 5,…