ayst123 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

自己做出来了，题目比较简单

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?

算是第一次一次AC的题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.分析:1

# Definition for singly-linked list.# class ListNode:# def __init__(self, x):# self.val = x# self.next = Noneclass Solution: # @param head, a ListNode # @return a boo

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.

比较简单，自己搞定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.分析：

自己做出来的，还可以f

自己原来想到了双指针法，后来看了下网上的解答，证明是对的。

这道题刚开始感觉有点复杂，后面还是做出来了。 不过看了网上的答案，有更易于思考的角度Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.For example,Giv

这题开始的思路时错的，后来看了

看了网上才想到分析： 刚开始想

看了网上的讲解一开始想一个一个去合并，复杂度是fa

Given an array and a value, remove all instances of that value in place and return the new length.The order of elements can be changed. It doesn't matter what you leave beyond the new length.

自己搞定Follow up for "Remove Duplicates":What if duplicates are allowed at most twice?For example,Given sorted array A = [1,1,1,2,2,3],Your function should return length = 5, and A is now

Find the contiguous subarray within an array (containing at least one number) which has the largest sum.For example, given the array [−2,1,−3,4,−1,2,1,−5,4],the contiguous subarray [4,−1,2,1] ha

Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length.Do not allocate extra space for another array, you must do this in place with

Find the contiguous subarray within an array (containing at least one number) which has the largest product.For example, given the array [2,3,-2,4],the contiguous subarray [2,3] has the largest

ZIJGiven a triangle, find the minimum path sum from top to bottom. Each step you may move to adjacent numbers on the row below.For example, given the following triangle[ [2], [3,4

参考了网上答案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}, r

Sort a linked list in O(n log n) time using constant space complexity.用归并算法，先找到

自己做chu lGiven a linked list, reverse the nodes of a linked list kat a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end should rema

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?分析： 题目比较简单，小的西晋

Follow up for "Unique Paths":Now consider if some obstacles are added to the grids. How many unique paths would there be?An obstacle and empty space is marked as 1 and 0 respectively in the

Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right which minimizes the sum of all numbers along its path.Note: You can only move either down or right at

A robot is located at the top-left corner of a m x ngrid (marked 'Start' in the diagram below).The robot can only move either down or right at any point in time. The robot is trying to reach the b

Given an index k, return the kth row of the Pascal's triangle.For example, given k = 3,Return [1,3,3,1].easy to solveclass Solution: # @return a list of integers def getRow

Given a non-negative number represented as an array of digits, plus one to the number.The digits are stored such that the most significant digit is at the head of the list.not hardrecursio

Given numRows, generate the first numRows of Pascal's triangle.  For example, given numRows = 5It's easy to solve.class Solution: # @return a list of lists of integers def generate(sel

Given a collection of integers that might contain duplicates, S, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must not contain dupli

Given a set of distinct integers, S, return all possible subsets.Note:Elements in a subset must be in non-descending order.The solution set must not contain duplicate subsets.For exa

QuestionHow would you print just the 10th line of a file?For example, assume that file.txt has the following content:Line 1 Line 2 Line 3 Line 4 Line 5 Line 6 Line 7 Line 8 Line 9 Line 10 You

QuestionGiven a text file file.txt that contains list of phone numbers (one per line), write a one liner bash script to print all valid phone numbers.You may assume that a valid phone number must appea

QuestionWrite a bash script to calculate the frequency of each word in a text file words.txt.For simplicity sake, you may assume:words.txt contains only lowercase characters and space ’ ’ characters.

QuestionGiven a text file file.txt, transpose its content.You may assume that each row has the same number of columns and each field is separated by the ’ ’ character.For example, if file.txt has the f

Get idea from Code Ganker′s (优快云) solution, also from this solutionQuestionGiven a 2D board and a word, find if the word exists in the grid.The word can be constructed from letters of sequentially ad

Get idea from Code Ganker′s (优快云) Solution, and Leetcote articleQuestionSuppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).You a

QuestionGiven an array with n objects colored red, white or blue, sort them so that objects of the same color are adjacent, with the colors in the order red, white and blue.Here, we will use the intege

Get idea from Code Ganker (优快云)′solutionQuestionFollow up for “Search in Rotated Sorted Array”: What if duplicates are allowed?Would this affect the run-time complexity? How and why?Write a function

Get idea from hereQuestionGiven a sorted array of integers, find the starting and ending position of a given target value.Your algorithm’s runtime complexity must be in the order of O(log n).If the tar