Trending February 2024 # What Is A Greedy Algorithm? # Suggested March 2024 # Top 5 Popular

You are reading the article What Is A Greedy Algorithm? updated in February 2024 on the website Hatcungthantuong.com. We hope that the information we have shared is helpful to you. If you find the content interesting and meaningful, please share it with your friends and continue to follow and support us for the latest updates. Suggested March 2024 What Is A Greedy Algorithm?

Introduction to Greedy Algorithm

Start Your Free Data Science Course

Hadoop, Data Science, Statistics & others

What is a Greedy Algorithm?

It is an algorithmic strategy used to make the best optional choice at a very small stage while eventually outputting a globally optimum solution. This algorithm picks the best solution feasible at that moment without regard to any consequences. The greedy method says that problem should be solved in stages wherein each one input is considered given that this input is feasible. As this approach only focuses on an immediate result with no regard for the bigger picture, it is considered greedy.

Defining the Core Concept

Till now, we know what it is and why is it named so. The below pointers will make you understand the greedy algorithm in a better way. By now, it has been very clear that the greedy algorithm only works when there is a problem; nevertheless, this approach is only applicable if we have a condition or constraint to that problem.

Types of Problems

Minimization Problem: Getting a solution to a problem is easy, given that all the conditions are met. However, when this problem demands a minimum result, it is then called a Minimization Problem.

Maximization Problem: A problem that demands the maximum result is known as the maximization problem.

Optimization Problem: A problem is called an optimization problem when it requires either minimum or maximum results.

Types of Solutions

Feasible Solution: Now, when a problem arises, we have many plausible solutions to this problem. Yet, taking into consideration the condition set on that problem, we choose solutions that satisfy the given condition. Such solutions that help us get results meeting the given condition is called a Feasible Solution.

Optimal Solution: A solution is called optimal when it is already feasible and achieves the objective of the problem; the best result. This objective could either be the minimum or maximum result. The point here to be noticed is that any problem will only have one optimal solution.

Core Components of Greedy Algorithm

Now when we have a better understanding of this mechanism, let’s explore the core components of a greedy algorithm that sets it apart from other processes:

Candidate set: An answer is created from this set.

Selection function: It selects the best candidate to be included in the solution.

Feasibility function: This section calculates if a candidate can be used to contribute to the solution.

An objective function: It assigns a value to a complete or a partial solution.

A solution function: This is used to indicate if a proper solution has been met.

Where does the Greedy Algorithm work the best?

It can be applied to the below-mentioned problems.

The Greedy approach can be used to find the minimal spanning tree graph using Prim’s or Kruskal’s algorithm.

Finding the shortest path between two vertices is yet another problem that can be solved using a greedy algorithm. Applying Dijkstra’s algorithm along with the greedy algorithm will give you an optimal solution.

Huffman Coding

Advantages

Knapsack Problem: Most commonly known by the name rucksack problem, it is an everyday problem faced by many people. Say we have a set of items and each has a different weigh and value (profit) to filled into a container or should be collected in such a way that the total weight is less than or equal to that of the container while the total profit is maximized.

Conclusion

It is best applicable when one needs a solution in real-time and approximate answers are “good enough”. Clearly, it minimizes time while making sure that an optimal solution is produced; hence it is more applicable to use in a situation where less time is required. Post-reading this article, one might have a fair idea about greedy algorithms. In addition, this post explains why it is regarded as the best framework that answers nearly all programming challenges along with helping you to decide the most optimal solution at a given point in time.

However, on the rough side, for applying the theory of greedy algorithms, one must work harder to know the correct issues. Although it’s a scientific concept that has logic, it also has an essence of creativity.

Recommended Articles

You're reading What Is A Greedy Algorithm?

What Is The Google Rankbrain Algorithm Update All About?

What is Google RankBrain AI

AI stands for Artificial Intelligence, and I will be using the acronym here to keep it easy. Before proceeding to the part where we will talk about Google not being able to understand what its own creation is doing, this section introduces BrainRank AI Search to readers who don’t know about search engine algorithms.

Search Engines like Google depend on hundreds of factors to bring the best possible results to anything you enter in the search box. Earlier they were dumb and focused just on keywords. But the keywords could also be dumb. For example, people can search for “explain top of the food chain”. This can easily confuse a search engine into assuming that maybe the person searching is asking something about food chains like restaurants so give him a list of top restaurants in the area

But the person is actually searching for the name of which, the top carnivore. The food chain starts with single cell animals, goes on to herbs, then herbivorous animals, carnivorous animals, humans and ends with a predator on the top.

Google and other search engines store plenty of information on their servers so that they can provide you with the results you want. For that, they check out many factors. So far, no artificial intelligence was involved. Among the hundreds of factors, it was ‘items in bold’, ‘headings’, ‘subheadings’, ‘repetition of a word or phrase’ and many such things.

If the person who is searching on Google, types in irrelevant things into the search box, the results were always garbage. The first principle of machines is if you feed garbage to machines, they’ll give out the garbage. You may search GIGO (garbage in, garbage out) for examples of this principle.

To tackle such situations, Google kept on making changes to its search algorithms and then secretly included BrainRank into it somewhere in 2024. It kept it a secret until recently. An event was held in March, and that is when they acknowledged that their engineers do not know how the thing works. It does send out wrong signals.

RankBrain is part of Google’s Hummingbird search algorithm, and is said to be the third-most important signal – the first probably being the quality of back-links. It will soon change the way SEO works.

Here is what Google RankBrain AI search algorithm does according to what I could grasp from my research. Instead of focusing on each search initiated, it focusses on the entire search session. Normally, to get proper results and to narrow down, many researchers use synonyms and words related to what they are searching. Like in the above example, one may use “topmost consumer in the food chain” and “what’s the highest level of food chain called”. He or she may use more keywords depending upon what the person wants to know.

So as the searches progress in the session, from the first search to nth search, Google RankBrain AI will start presenting more and more relevant pages to the researcher. This may include pages that do not even include the keyword but provides more related information about the same.

How does Google RankBrain work

Here comes the problem. The creators of the RankBrain AI themselves do not understand how it works. Since it is limited to search, it is not a scary situation. But imagine creating a similar thing in a domain that is related to weapons? What are the odds against a machine growing mature enough to take its own stand against the creators? What if we create AI-based robots for the army, mass produce them and some things go wrong to make them turn against their own generals? It doesn’t look right. The chances are 50:50 – a good amount of risk.

In an event called SMX, Google’s Paul Haahr, who goes by the handle @haahr on Twitter told many interesting things about the algorithm and acknowledged that Google engineers who work on RankBrain don’t know how it works. Either Haahr was not willing to share information or the creators really don’t know much about their creation.

If later is the case, it should ring some alarm bells. Already many scholars have raised their fears on AI and the fast growing research in the domain. They petitioned governments to stop funding projects leading to strong and super AI.

Google RankBrain AI is just the beginning!

What Is A Dictionary Attack?

To authenticate to a website, you need to provide a username and password. The site then checks the authentication details that you have provided by comparing them with the details it has stored in its database. If the details match, access is granted. If the details don’t match, access is denied.

Unfortunately, data breaches are a relatively common occurrence. Data breaches can be a big problem because one of the bits of data most commonly targeted is the user data, specifically the list of usernames and passwords. If the passwords are just stored as is, in plaintext then anyone with access to the database can then access the account of any other user. It’s as if they were handed a keyring with the key to every door in an apartment building.

Helpfully this also means that if an attacker does breach the database, they don’t get a list of immediately useful passwords, they get hashes instead. To be able to use these hashes they need to be cracked.

Cracking password hashes with smarts

Cracking a password hash is the process of working out what the original password is that the hash represents. Because there’s no way to reverse the hash function and turn the hash into the password. The only way to crack a hash is to guess the password. One method is to use a brute force attack. This literally involves trying every possible password. That means starting from “a”, trying every letter, in both cases, and every number and symbol. Then the attacker needs to try all two-character combinations, three-character combinations, and so on. The increase in possible combinations of characters is exponential each time you add a character. This makes it difficult to efficiently guess long passwords even when fast hashing algorithms are used with powerful GPU cracking rigs.

Some effort can be saved by looking at the password requirements of the site and not trying passwords that would be too short to be allowed or that don’t feature a number, for example. This would save some time and still fits in the class of a brute force attack trying all allowed passwords. Brute force attacks while slow, will – if left long enough with a lot of processing power – eventually crack any password as all possible combinations will be tried.

The problem with brute force attacks is that they’re not very smart. A dictionary attack is a variant that is much more targeted. Instead of just trying any possible password, it tries a list of specified passwords. The success of this type of attack depends on the list of passwords, and the dictionary in question.

Making educated guesses

Password dictionaries typically are built from previously cracked passwords from other data breaches. These dictionaries can contain thousands or millions of entries. This builds on the concept that people are bad at creating unique passwords. Evidence from data breaches does show this to be the case too, unfortunately. People still use variations on the word “password”. Other common topics are sports teams, names of pets, place names, company names, hating your job, and passwords based on the date. This last one specifically tends to happen when people are forced to regularly change their passwords.

Using a password dictionary massively reduces the number of guesses that need to be made in comparison to a brute-force attack. Password dictionaries also tend to contain both short and longer passwords meaning that some passwords might be tried that would not be reached even with years or brute force guessing. The approach proves successful as well. Stats vary based on the data breach and the size and quality of the dictionary used but success rates can exceed 70%.

Conclusion

A dictionary attack is a targeted variation of a brute force attack. Rather than attempting all possible character combinations, a subset of character combinations is tested. This subset is a list of passwords that have previously been found and if necessary cracked in past data breaches. This massively reduces the number of guesses to be made while covering passwords that have been used before, and in some cases, seen often. A dictionary attack doesn’t have as high a success rate as a brute force attack. That, however, assumes you have unlimited time and processing power. A dictionary attack tends to get a decently high success rate much faster than a brute force attack can. This is because it doesn’t waste time on extremely unlikely combinations of characters.

One of the main things you should do when coming up with a password is to make sure that it wouldn’t appear on a wordlist. One way to do that is to make a complex password, another is to make a long password. Generally, the best option is to make a long password made up of a few words. It’s just important that those words don’t make an actual phrase as that might be guessed. They should be completely unrelated. It’s recommended that you choose a password over 10 characters with 8 as the absolute bare minimum.

What Is A Company Merger?

FYI

A merger can benefit companies by increasing profits, enhancing expertise, expanding market share, diversifying products and minimizing redundancy.

Key Takeaway

A merger is when two companies combine to form one new company. An acquisition is when one company buys out and controls another company.

Did You Know?

There are five main types of company mergers: conglomerate mergers, horizontal mergers, vertical mergers, market extension mergers and product extension mergers.

More examples of major mergers

We’ve covered a few examples of mergers, but they only tell part of the story. Some of the largest corporate mergers in history can highlight the scope of these deals and what companies stand to benefit from going through the process. When mergers reach this scale, governments get involved, as the rippling effects of the merger can shake up entire economies.

America Online and Time Warner

This merger happened in 2000 and began the massive consolidation of internet service providers. At the time, America Online was the largest ISP in the business, but cable providers were beginning to realize that internet services were the future. Time Warner was valued at $164 billion and was one of the biggest cable companies in the United States.

This merger put two powerhouses together, and the new company created the roadmap for utilizing cable infrastructure to rapidly and dramatically improve internet access and performance.

Pfizer and Warner-Lambert

This is another major merger that happened in 2000. In this case, both companies existed in the pharmaceutical space. Originally, Warner-Lambert was planning to sell to a different company, American Home Products. That deal collapsed, and Pfizer swooped in to complete a merger of its own.

The merger went through for $90 billion, and the two companies were able to consolidate profits for production and distribution of the cholesterol medication known as Lipitor.

Exxon and Mobil

This merger happened a year earlier than some of the other giants’ mergers ― in 1999. These were already two of the largest oil refinery and distribution companies in the world. Their merger consolidated those resources, and the impact was so great that it changed the price of crude oil forever. That was the motivation for the merger, as it reallocated more than 2,000 gas stations across the U.S. You might recognize the resulting company, ExxonMobil, as the result of this merger.

Disney and Fox

The Disney and Fox merger was announced in 2023 to the tune of $52.4 billion. The price eventually rose to $71.3 billion before the deal was finalized, making it one of the largest mergers in history. It also represented one of the largest industry consolidations ever recorded. Disney and Fox were already two of the three largest media content owners in the world. With this merger, they became a superpower, with ownership of more movie and TV intellectual properties than any other organization in history so far.

What should you consider with mergers and acquisitions?

You might be happy with your current business structure and operations, but you never know when a potentially appealing merger or acquisition opportunity might arise. If one does, ask yourself the following questions:

Will the shifts in leadership and control be worth the potential benefits?

Is an acquisition worth it compared to a merger? 

What is your current situation? If it is fine, you might want to continue as is.

Whatever answers instinctively feel correct to you should lead your future actions. Though history is full of mergers and acquisitions, plenty of successful businesses have been independent from the start.

Max Freedman contributed to this article. Source interviews were conducted for a previous version of this article.

What Is A Mac Address?

If you’ve ever gone through the settings on your home router, we’d recommend you do, as some can come with insecure default settings and passwords. You may have noticed a feature called MAC filtering or something similar. You’d be forgiven for assuming that this setting prevented Apple’s Macs from connecting to your network or restricted it so only Macs could connect to your network.

Despite the potentially confusingly similar name, MAC has nothing to do with Apple. MAC is short for Media Access Control, and a MAC address is essential in computer networking. Those of you vaguely familiar with networking concepts may assume that IP addresses are the only form of address used to communicate over a computer network. This isn’t the case, though. IP addresses are used for routing traffic between networks. Still, devices use MAC addresses to route data within a network.

What Is a MAC Address?

A MAC address is part of the layer 2 addressing scheme on the OSI model. Layer 2 is used for local communication over a single network. In contrast, layer 3, with its IP addresses, is used for inter-network communications. MAC addresses have a simple structure made up of 12 hexadecimal characters. In most cases, a MAC address will be displayed with pairs of hexadecimal characters separated by a colon “:.” For example, a MAC address may look like this “00:20:91:AB:CD: EF”. Less often, MAC addresses may be separated by a hyphen and, in some cases, not separated at all.

Note: Hexadecimal means that the following characters are allowed “0123456789ABCDEF”. These make up a base 16 system. Conveniently, this means that one 8-bit byte of data can be represented by 2 hexadecimal characters.

A MAC address is divided into two parts, split down the middle. The MAC address’s first half identifies the device’s “vendor, manufacturer, or other organization.” It is an OUI, or Organisationally Unique Number assigned, upon request, by IEEE. All network cards produced by a manufacturer will have a MAC address starting with the same six hexadecimal characters.

The second half of the MAC address is “unique” and assigned when a device is made. The quotes are necessary because, with just 12-bits of address space remaining, there are only 16,777,216 possible combinations. This means that duplicates are likely with high-volume manufacturing. Thankfully, the MAC address is only used in local connections and is never used for inter-network communications. This means that a MAC address doesn’t have to be unique in the world, just unique on the network. It is possible to have an issue, but it’s unlikely.

The Difference Between IP and MAC Addresses

Every device on a network will occasionally broadcast its MAC address to indicate to other devices that it is connected to the network. These broadcasts are never extended out of a network. For this reason, there is no risk of anyone on the internet knowing your MAC address. The information would only theoretically be helpful for someone on the same local network as you.

Note: By network, we specifically mean local network, such as your home Wi-Fi network, not your ISP network.

IP addresses are the addressing scheme used to communicate across networks. This means that your IP address could be helpful to an attacker on the internet, potentially target you with DDOS attacks. For this reason, you shouldn’t share your public IP address where possible.

Be aware, however, that you can’t really avoid doing so if you send network traffic to someone, as they need to know your IP address to send a response back. IP addresses are also globally unique, though there is the caveat to the reserved private address ranges, which are treated more similarly to MAC addresses.

Privacy Issues

One of the issues with wireless connections such as Wi-Fi is that when your device isn’t connected to a network, it tries to search for known networks to connect to. This functionality enables your mobile phone to automatically reconnect to your home Wi-Fi when you get within the range, which is useful, but there’s also a privacy issue. To do this, your device regularly broadcasts the names of all Wi-Fi networks it has been configured to connect automatically. It says, “I want to connect to these networks. Are any of you out there?”

This sounds fine until you realize your device does this with a packet that uses its MAC address. This means that a large organization with lots of Wi-Fi access points or devices to listen to Wi-Fi traffic can track the movements of specific devices around a building, city, or country. Or even internationally, wherever they have the infrastructure.

To get around this, modern devices, especially mobile devices, tend to randomize their MAC address when performing these broadcasts. This denies anyone the ability to track your movements by monitoring the movement of a single MAC address. MAC randomization is even generally enabled by default.

You may remember that we said earlier that the MAC address was hard coded when the network device was manufactured. Both desktop and mobile operating systems allow you to manually override the MAC address. This is useful and good for privacy. It does have one minor consequence, though. It means that MAC filters on Wi-Fi routers are generally easy to bypass.

A Humorous Side Note

A lot of organizations have been assigned OIDs by IEEE. Many companies will be the ones you’d expect, the actual hardware manufacturers. Many will be companies you’ve never heard of too. There are some interesting ones, though. One such interesting one is the NSA. Yes, everyone’s favorite three-letter American agency is the National Security Agency. They have the OID “00-20-91”.

Many network monitoring systems translate the first half of a MAC address into the actual textual name of the organization it represents. This is because it’s slightly more accessible for people to read and spot patterns this way. It also means that if you configure your device’s MAC address, to begin with, “00-20-91,” it will show up in any monitoring system as being from the NSA. This has been used to prank unwary system admins in companies. Technically, there is no legal restriction or issue with doing this yourself. We don’t necessarily recommend it, though, especially in corporate environments, the little prank might not be appreciated.

Conclusion

A MAC address is a 48-bit address used for layer 2 communications. Being a layer 2 addressing scheme, it never gets transmitted beyond the local network. However, a MAC address must be unique on a network. The MAC address has two halves. The first half identifies the device manufacturer, while the second half is a network special device identifier.

MAC addresses are assigned to a network adaptor when they are manufactured. However, most operating systems feature functionality to override the given MAC address with a custom one. MAC addresses are displayed as 12 hexadecimal digits, typically separated in pairs by colons or hyphens.

What Is A Flagship To You?

What’s the best Android phone? We tested hundreds, here are our top 8

The best

What is a flagship device?

The first thing to do when you want to better understand a concept is to start with its official definition. The first three entries for “flagship” pertained to ships and naval vessels, but the fourth caught my attention: According to chúng tôi a flagship can be defined as “the best or most important one of a system or group”.

This short-and-sweet denotation is effective and is, more or less, how AA team members see it, too. However, the question quickly becomes whether a flagship device is the best a company has to offer or the best of all devices on the market. These two possibilities have become the two schools of thought surrounding flagship designation, but neither are necessarily wrong.

ZTE Axon 7 vs OnePlus 3

Versus

Some say a flagship is basically everything an OEM has to offer in a single device

In Joe’s eyes, a flagship is basically everything an OEM has to offer in a single device. However, Kris said that each company chooses the device that will be its flagship. More often than not, this means that the device carries either some or all of the best specs available at the time; for instance, a Samsung Galaxy device having 4GB of RAM rather than 6GB like the OnePlus 3 doesn’t mean that the Galaxy device isn’t a flagship since 4GB of RAM is already considered more than sufficient by most standards. A flagship must also be an improvement over the previous year’s model.

A flagship is often judged by how it stacks up against its competition

Kris went on to explain that the concept of flagship invites us to compare a device against other devices that have been designated as flagships. Therefore, a flagship device is often judged by how it stacks up against its competition. However, cost is often irrelevant to a device’s designation as a flagship, especially with the growing number of manufacturers that are making so-called budget flagships. It’s worth nothing that when cost is considered, it’s usually as a mere reference point by which we can compare devices of a single class and assess their value.

The best of the best in the industry

What are the characteristics that separate a flagship from competing devices in the smartphone market?

Since all smartphone manufacturers can designate devices as flagships, there’s inevitably going to be a lot of comparisons made when it comes to the flagship offerings of the entire industry. In that vain, some believe flagship status delineates a small group of devices from all other available devices, or separates the few from the many. But what are the defining characteristics that separate a flagship device from competing devices in the smartphone market? Android Authority team members Brian Reigh, Bogdan Petrovan, Nirave Gondhia, and Gary Sims attempt to answer this question.

According to Brian, a flagship device must be mostly congruent with what are considered top-shelf specs in the mainstream smartphone market. His example is that it’s difficult to consider a device with a 1080p display a flagship when many of the most popular OEMs have moved to Quad HD displays. Bogdan mentioned that the overall experience has a lot to do with it; he said that while specs and performance are driving factors, marketing and brand perception can be distinguishing factors as well. Similarly, Nirave explains that the top specs seen in the smartphone market — he mentions the Qualcomm Snapdragon 820 specifically — should be seen in a flagship device rather than lower-tier hardware.

Marketing and brand perception can be important factors as well

Gary had a unique perspective of flagships, but one that still applies to an industry-level designation. In Gary’s view, only Android devices can be flagships, and this is because OEMs that produce Android devices are competing with Apple’s iPhone, which is considered a premium device despite needing much less RAM and less impressive specs than today’s premium Android smartphones. When it comes down to it, Gary says that a flagship is an Android smartphone that’s the greatest competition to the iPhone in terms of features, innovation and price.

Samsung Galaxy S7 review

Samsung Galaxy S7 Edge review

Tiers of flagship devices

[related_videos align=”right” type=”custom” videos=”698369,709985,705570,705052″]Jimmy Westenberg largely agrees with the idea that flagship is the best a manufacturer has to offer; however, he explained that a company can have multiple flagships by designating a flagship device in each price/specification tier. This means companies that produce many different devices at varying price levels could have a budget flagship, a mid-range flagship, and a premium flagship. On the one hand, having low- and mid-cost flagships might contradict the concept of flagship if you see a flagship as being top-of-the-line. On the other hand, both the Samsung Galaxy S7 Edge and the OnePlus 3 have been referred to as flagships, so Jimmy’s explanation has merit.

A flagship is the best device that an OEM has to offer.

A flagship sports many of the top specs currently available.

A flagship is an Android smartphone that can compete with Apple’s iPhone.

A flagship device doesn’t have any compromises.

A flagship device is the best of all devices within a certain price range.

A flagship is a device that’s made to have broad commercial appeal.

A flagship device has a very strong, prominent marketing campaign.

What is a flagship to you?

Update the detailed information about What Is A Greedy Algorithm? on the Hatcungthantuong.com website. We hope the article's content will meet your needs, and we will regularly update the information to provide you with the fastest and most accurate information. Have a great day!