freecodecamp medium

DoS (Denial of Service) is a network attack that uses a reasonable amount of service resources to prevent legal users from receiving service responses. DoS attacks may occur in the following ways:* The attacked host has a large number of TCP connections waiting;* The system resources of the attacked host are heavily occupied, causing system pauses;* The network is filled with a large number of useless data packets. The source address is a fake address;* Network congestion is caused by heavy tra

advance, without long-tail words searched by these users. As a result, these popular words may not compete with other more advantageous websites, and those that should belong to their own traffic, the web pages with long-tail words placed in important locations are taken. In a large and medium-sized website, it is unwise to optimize resources in favor of popular keywords. From the perspective of maximizing website traffic, there is no doubt that long

Learning Algorithms from scratch: 10 sorting algorithms (medium)Author: matrix67 Date: 2007-04-06 font size: small, medium, and large. This article is divided into four sections by the gorgeous split line. For the O (nlogn) sorting algorithm, we will introduce Merge Sorting in detail and prove the time complexity of Merge Sorting. Then we will briefly introduce heap sorting, and then give the basic idea and

[LeetCode] 003. Longest Substring Without Repeating Characters (Medium) (C ++/Java/Python), leetcoderepeating Index: [LeetCode] Leetcode index (C ++/Java/Python/SQL)Github: https://github.com/illuz/leetcode 003. Longest_Substring_Without_Repeating_Characters (Medium) Link: Title: https://oj.leetcode.com/problems/Longest-Substring-Without-Repeating-Characters/Code (github): https://github.com/illuz/leetcod

[LeetCode] 012. Integer to Roman (Medium) (C ++/Java/Python), leetcodepython Index: [LeetCode] Leetcode index (C ++/Java/Python/SQL)Github: https://github.com/illuz/leetcode012. Integer_to_Roman (Medium) Link: Title: https://oj.leetcode.com/problems/integer-to-roman/Code (github): https://github.com/illuz/leetcode Question: Convert the decimal to the number of Rome. Analysis: Simulate it. "The Basic symbols

[LeetCode] 011. Container With Most Water (Medium) (C ++/Java/Python), leetcodecontainer Index: [LeetCode] Leetcode index (C ++/Java/Python/SQL)Github: https://github.com/illuz/leetcode 011. Container_With_Most_Water (Medium) Link: Title: https://oj.leetcode.com/problems/container-with-most-water/Code (github): https://github.com/illuz/leetcode Question: For some baffle plates, select two baffle plates to

30 thousand kilometers. magotan's replacement cycle is shorter and the cost is higher. At the same time, magt's working hours can be regarded as the daily price of medium-sized vehicle maintenance. The hourly fee for a normal maintenance is about 400 yuan, and the hourly fee for the replacement of the brake oil of only 60 yuan has actually reached 400 yuan. The hourly fee for the gearbox oil of about 600 yuan is not comparable to that for normal vehi

Many project managers who have worked on small and medium-sized projects have such feelings that it is difficult to maintain the software during the maintenance period. Why? 1. The customer's final requirements have changed too much at the beginning of requirement analysis. 2. the buckets that are not tested in the software development project cause some error data in the database. Then some small tools of software engineers were corrected. But the

[LeetCode] 039. Combination Sum (Medium) (C ++), combinationleetcode Index: [LeetCode] Leetcode index (C ++/Java/Python/SQL)Github: https://github.com/illuz/leetcode 039. Combination Sum (Medium) Link: Title: https://leetcode.com/problems/combination-sum/Code (github): https://github.com/illuz/leetcode Question: A positive integer set and a target number are given. You can select a number from the set so

The Wall (medium)Heidi the Cow is aghast:cracks in the northern Wall? Zombies gathering outside, forming groups, preparing their assault? This must not happen! Quickly, she fetches her HC2 (Handbook of Crazy Constructions) and looks in the right chapter:How to build a wall: Take a set of bricks. Select one of the possible wall designs. Computing the number of possible designs is left as a exercise to the reader. Place bricks on top of

3Sum (Medium) descriptionGiven an array nums of n integers, is there elements a, B, C in nums such that A + B + c = 0? Find all unique triplets in the array which gives the sum of zero.Note:The solution set must not contain duplicate triplets.Example:Given array nums = [-1, 0, 1, 2, -1, -4],A solution set is:[ [-1, 0, 1], [-1, -1, 2]]AnalysisThe first is the most easily thought of brute force, by iterating through the array nums , sequentially deter

Isequaltostring:[contact name]]) {[Array removeobject:contact];Returnc = Contact;NewKey = key;}}}[[_contactlist Objectforkey:newkey] removeobject:c];}Delete all contacts under a group-(void) Removeallcontactsbygroupname: (NSString *) GroupName {[_contactlist Removeobjectforkey:groupname];}Show All Contacts-(void) Showallcontacts {Nsarray *allkeys = [_contactlist AllKeys];Nsarray *newarray = [AllKeys sortedarrayusingselector: @selector (compare:)];For (NSString *key in NewArray) {Nsmutablearray

Palindrome Linked ListImplement a function to check if a linked list is a palindrome.ExampleGiven 1->2->1 , return TrueChallengeCould do it in O (n) time and O (1) space?////1\find out the medium index of Linked list2\ reverse the right part of linked list in place3\compare their value;/*** Definition for singly-linked list. * public class ListNode {* int val; * ListNode Next; * ListNode (int X) {val = x;}}*/ Public classSolution {/** * @paramhead

former group of technology represents the Java language to the network IO Model encapsulation (see this series of article "Architecture Design: Inter-system Communication (3)--io communication model and Java Practice", "Architecture design: Inter-system Communication (4)-- IO communication model and Java practice Medium, Architecture Design: Inter-system Communication (5)--io communication model and Java practice in the next chapter). Netwo

IPMI from drive to Application (medium )In the previous article, we talked about the IPMI underlying hardware connection and the implementation of the kernel driver, which facilitated the application developer by simply opening the operation with standard device files and invoking the available IOCTL to the BMC Send the request or read the response result.In addition to using this approach, application development engineers can leverage existing open

QQ:1187362408 welcomes technical exchanges and learningGrid++report Medium (Grid++report):Todo:1,grid++report: Introduction (Grid++report is a high-performance report development tool, especially suitable for information management systems, such as ERP, invoicing, financial and other software report development. The paper has been specially implemented for the bill set, and it is also a good tool to realize the paper printing. Grid++report is a fully

Small and Medium network system integrationBackground Description:650) this.width=650; "src=" Http://img.my.csdn.net/uploads/201101/2/0_1293972288hRzc.gif "/>company Environment and requirements: 1 , the company has 2 departments, Finance Department, marketing department, and manager's office;2 , in order to ensure that the financial Department of Computer Security, the marketing department is not allowed to access the Finance Department host;3 , the

comedy writer, the students have seen the happy, listen very readily! Although the back-end service, but through the 4-month learning process, Brother Ho will always pay attention to each student's learning situation, in accordance with the actual individual, Targeted employment guidance and recommendations. At the same time, Brother Hao also set a 4 months after the students to achieve a small goal (want to know what is it?) Come in soft I tell you!) and look forward to them all to reach. Cl

First look at the site architecture diagram:650) this.width=650; "Src=" Http://s4.51cto.com/wyfs02/M01/83/AF/wKiom1d6Ma7gWzEWAAHVOh56AxA285.jpg-wh_500x0-wm_3 -wmp_4-s_2403683709.jpg "title=" small and medium-sized website analysis and optimization. jpg "alt=" wkiom1d6ma7gwzewaahvoh56axa285.jpg-wh_50 "/>The above site structure widely used in large-scale Web site, this article from the framework of each layer of analysis of the mainstream technology an

Brain Network (Medium)Further on zombie thought processes yielded interesting results. As we know from the previous problem, the nervous system of a zombie consists of n brains and m brain connectors Joining some pairs of brains together. It was observed this intellectual abilities of a zombie depend mainly on the topology of its nervous system. More precisely, we define the distance between, Brains u and v (1≤ u , v ≤ n ) as the minimum