ohyeslk的专栏

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 roman numeral, convert it to an integer.Input is guaranteed to be within the range from 1 to 3999.罗马数字转整数 = =

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->1-

Given a binary tree, return the inorder traversal of its nodes' values.For example:Given binary tree {1,#,2,3}, 1 \ 2 / 3return [1,3,2].Note: Recursive solutio

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

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.1.递归

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 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删除链表中的重复点

Given a linked list, determine if it has a cycle in it.Follow up:Can you solve it without using extra space?

Follow up for N-Queens problem.Now, instead outputting board configurations, return the total number of distinct solutions.经典的八皇后问题这个比n皇后1简单 先做这个。规则是 行、列、正反对角线上都只能有一个皇后。1.常规做法。 递归

Sort a linked list using insertion sort.用插入排序来排链表/** * Definition for singly-linked list. * public class ListNode { * int val; * ListNode next; * ListNode(int x) { * val

Given a binary tree, find its minimum depth.The minimum depth is the number of nodes along the shortest path from the root node down to the nearest leaf node./** * Definition for binary tree

Given an array of integers, find two numbers such that they add up to a specific target number.The function twoSum should return indices of the two numbers such that they add up to the target, whe

Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete at most two transactions.Note:You may

Say you have an array for which the ith element is the price of a given stock on day i.If you were only permitted to complete at most one transaction (ie, buy one and sell one share of the stock),

Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100"1.sum的数组长度不可以定义，否则没有进位的数最前面会有一个空格2.Char和string的转换3.进位表示法

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. You m

Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.The brackets must close in the correct order, "()" and "()[]{}" are all va

Implement pow(x, n).最先想到的就是d

Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in order.You may assume no duplicates in the array.

Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the array which gives the sum of target.Note:Element

Given a binary tree, determine if it is height-balanced.For this problem, a height-balanced binary tree is defined as a binary tree in which the depth of the two subtrees of every node never diffe

You are climbing a stair case. It takes n steps to reach to the top.Each time you can either climb 1 or 2 steps. In how many distinct ways can you climb to the top?爬n层楼梯 每次能走1huo

Given two binary trees, write a function to check if they are equal or not.Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complete as many transactions as you like (ie, buy on

Copy List with Random Pointer Total Accepted: 14031 Total Submissions: 61754My SubmissionsA linked list is given such that each node contains an additional random pointer which could poi

Given an array of integers, every element appears twice except for one. Find that single one.Note:Your algorithm should have a linear runtime complexity. Could you implement it without using extra

Given a binary tree, find its maximum depth.The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly

Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string.If the last word does not exist, return 0.Note: A word is

Reverse digits of an integer.Example1: x = 123, return 321Example2: x = -123, return -321click to show spoilers.Have you thought about this?Here are some good questions to ask before coding.

Given an array S of n integers, are there elements a, b, c in S such that a + b + c = 0? Find all unique triplets in the array which gives the sum of zero.Note:· Elements in a triplet (a,b,c) must