text stringlengths 1 330k |
|---|
You can even gauge what kind of fragrances someone likes by knowing what they currently use. |
Tip # 2: Sample around the category of scents you are looking for. If it is a woody fragrance for men, shop around or get online reviews about woody fragrances. If it is a floral scent for women, get online reviews also. |
Tip # 3: As you are shopping around for a gift scent, keep in mind certain aspects like PRICE, LONGEVITY and LIKEABILITY of a fragrance. There are fragrances that receive massive thumbs up from everyone who comes across them while others spark MIXED REACTIONS. |
For gift scents, always go for those scents that are easy to like. The tip is to keep it SIMPLE. Refrain from complicated scents or those scents that need a refined nose to understand it. Trust your judgment and only hope the other person would like the gift. |
perfume gift setTip # 4: Choose between buying a fragrance gift set or just a fragrance bottle. For men, a gift set can have the perfume bottle, a body lotion and an aftershave. For Women the set would have the perfume bottle and the body lotion. |
Tip # 5: Once you have a fragrance in mind, always ensure to shop from a trusted online or physical store. There are so many fake fragrances flooding the Kenyan Market nowadays it is even hard to know how the legitimate fragrance smells like.Find out more on how to spot a fake fragrance on my article |
Tip # 6: You do not need to break your bank to get someone a designer fragrance. During this festive season, you will always find items on SALE including fragrances. Always ensure to inquire if an item is on sale; you can get massive discounts especially on items with gift sets. |
P.S: To get original fragrances at competitive prices here in Kenya, check out Scents Lifestyle |
Please follow and like us: |
Leave a Reply |
Assault Rifles Are Not Protected By The Second Amendment |
Any time the issue of gun safety is brought up in the United States, politicians mention the Second Amendment. Republicans tend to use the Second Amendment as a rationale for not taking any steps to increase gun safety. Democrats tend to mention their respect for the Second Amendment while stating the common-sense pr... |
“What?” you say. “How could that be?” The current interpretation of the Second Amendment, both by the media (regardless of partisanship lean) and the Supreme Court (the people who really matter), is that the Second Amendment protects individuals’ rights to own guns for self-defense purposes. This is broadly accepted... |
What changed? A right-wing movement and right-wing judges. After a decades-long effort to sway public opinion, elected officials, and groom right-wing judges, the NRA, with a massive assist from the Federalist Society and other right-wing organizations, finally got their desired result. |
In Heller, the Supreme Court, by a 5-4 majority, held that the Second Amendment protects an individual’s right to own a gun for self defense purposes and invalidated some provisions of a Washington, DC law that made it illegal to possess handguns in the city. The opinion is not good for a number of reasons: it misread... |
But here’s the thing: Heller is currently the law of the land. Whether, like me and plenty of others, you think it’s a bad decision or it’s the masterpiece of a legal genius, courts across the country are bound to follow it. Even Heller, however, does not prevent the federal government or states from enacting bans on... |
Some gun fanatics claim that any law that would outlaw or make it more difficult to obtains guns, ammunition, or accessories is a violation of the Second Amendment. These arguments, often by people claiming to love and want to protect the Constitution, overlook our legal system and how it’s the courts’ job to interpre... |
Scalia’s majority opinion in Heller makes it crystal clear that the right to “keep and bear arms,” is not absolute. “Like most rights, the right secured by the Second Amendment is not unlimited.” 128 S. Ct. at 2816. “[N]othing in our opinion should be taken to cast doubt on longstanding prohibitions on the possessio... |
Heller’s explicit limitations on the scope of the Second Amendment mean that there is no constitutional impediment to banning assault rifles. |
Many lower courts (district courts and courts of appeals) have upheld bans on assault rifles. For example, in Kolbe v. Hogan, the Fourth Circuit, en banc, upheld Maryland’s post-Sandy Hook ban on assault weapons and high-capacity magazines. The majority opinion, which had the support of ten judges versus four dissent... |
Because assault rifles are not protected by the Constitution, the only impediments to passing bans on assault rifles, which will save lives, is public opinion and political power. Public opinion is increasingly in favor of banning assault weapons. Federally and in many states, political power prevents any such action... |
If everyone who supports gun safety votes for politicians who support gun safety laws, we’ll be able to effect the change we want to see in the world. There are plenty of organizations doing great work on this front, including Everytown, Moms Demand Action, and March For Our Lives. The next time there’s a gun massacr... |
*If you don’t think Scalia was outcome-oriented, read United States v. Lopez (a 1995 case in which Scalia voted with the majority that Congress could not impose gun-free zones around schools because the Commerce Clause of the Constitution did not grant it that power) and Gonzales v. Raich (a 2005 case in which Scalia v... |
One thought on “Assault Rifles Are Not Protected By The Second Amendment |
Leave a Reply |
You are commenting using your account. Log Out / Change ) |
Google photo |
Twitter picture |
Facebook photo |
Connecting to %s |
Which is the fastest algorithm to find out prime numbers using C++? I have used sieve's algorithm but I still want it to be faster! |
• An old article I found, but looks interesting: Fun With Prime Numbers – Mvcoile Jun 30 '12 at 12:37 |
• 28 |
@Jaider this fails for numbers as low as 7 (111). It also fails for 1001=9. And clearly it fails for almost all of the primes in general (does not cover the case 2^p - 1, which are Mersenne prime numbers - classically generated examples - that will always be of the form 111...1) – BlackSheep Nov 21 '12 at 17:07 |
• 9 |
There's a regex for that – Corey Ogburn Jul 9 '14 at 20:50 |
• 2 |
Hahahaha you gave me a good laugh there @Hot Licks – coder guy Oct 8 '15 at 17:39 |
• 1 |
@Kasperasky - You did not mention which Sieve? You probably mean Sieve of Eranthoses! – user2618142 Nov 6 '17 at 9:35 |
14 Answers 14 |
A very fast implementation of the Sieve of Atkin is Dan Bernstein's primegen. This sieve is more efficient than the Sieve of Eratosthenes. His page has some benchmark information. |
• 10 |
Actually I don't think primegen is the fastest, or even the second-fastest; yafu and primesieve are both faster in general, I think, and certainly over 2^32. Both are (modified) sieves of Eratosthenes rather than the Atkin-Bernstein sieve. – Charles Aug 19 '11 at 4:29 |
• 5 |
Primesieve Sieve of Eratosthenes (SoE) is the very fastest algorithm possible and will always be faster than any implementation of the Sieve of Atkin SoA, including Bernstein's as linked in this answer because primesieve reduces the number of operations compared to SoA: For the 32-bit number range (2^32 - 1), prime... |
• 7 |
Continued: Bernstein only compared the SoE using the same effective wheel factorization as for the SoA, which is a 2;3;5 wheel, use of which wheel results in about 1.83 billion culls over the 32-bit number range; this makes the SoA about 30% faster when comparing this restricted version of SoE for equivalent other ... |
• 6 |
Continued2: The SoA con not have higher factor wheel factorization used to make much of a difference as the 2;3;5 factorization wheel is a "baked-in" part of the algorithm. – GordonBGood Dec 6 '13 at 3:18 |
• 4 |
@Eamon Nerbonne, WP is correct; however, just having a slightly better computational complexity doesn't make a faster algorithms for general use. In these comments, I am referring to that maximum wheel factorization of the Sieve of Eratosthenes (SoE) (which is not possible for the Sieve of Atkin- SoA) makes for sli... |
If it has to be really fast you can include a list of primes: |
If you just have to know if a certain number is a prime number, there are various prime tests listed on wikipedia. They are probably the fastest method to determine if large numbers are primes, especially because they can tell you if a number is not a prime. |
• 2 |
A list of all primes? I think you mean a list of the first few primes... :) – j_random_hacker Jan 18 '09 at 4:19 |
• 8 |
If you call 100000000 a few, then yes. :) – Georg Schölly Jan 18 '09 at 7:35 |
• 53 |
surely 100000000 is "a few" comparing to infinity ;) – Tim Jan 21 '12 at 16:08 |
• 9 |
Why do you think that the Sieve of Atkin (SoA) is faster than the Sieve of Eratosthenes (SoE)? It certainly isn't when one just implements a program using the pseudo code as in the Wikipedia article you linked. If the SoE is implemented with a similar level of possible optimizations as are used with the SoA, then t... |
He, he I know I'm a question necromancer replying to old questions, but I've just found this question searching the net for ways to implement efficient prime numbers tests. |
Until now, I believe that the fastest prime number testing algorithm is Strong Probable Prime (SPRP). I am quoting from Nvidia CUDA forums: |
One of the more practical niche problems in number theory has to do with identification of prime numbers. Given N, how can you efficiently determine if it is prime or not? This is not just a thoeretical problem, it may be a real one needed in code, perhaps when you need to dynamically find a prime hash table size withi... |
The common practical solution to this problem is a simple test called an Euler probable prime test, and a more powerful generalization called a Strong Probable Prime (SPRP). This is a test that for an integer N can probabilistically classify it as prime or not, and repeated tests can increase the correctness probabilit... |
The test can be changed from a probabilistic rejection into a definitive proof of primality by precomputing certain test input parameters which are known to always succeed for ranges of N. Unfortunately the discovery of these "best known tests" is effectively a search of a huge (in fact infinite) domain. In 1980, a fir... |
See here for more info: http://primes.utm.edu/prove/prove2_3.html and http://forums.nvidia.com/index.php?showtopic=70483 |
If you just need a way to generate very big prime numbers and don't care to generate all prime numbers < an integer n, you can use Lucas-Lehmer test to verify Mersenne prime numbers. A Mersenne prime number is in the form of 2^p -1. I think that Lucas-Lehmer test is the fastest algorithm discovered for Mersenne prime n... |
And if you not only want to use the fastest algorithm but also the fastest hardware, try to implement it using Nvidia CUDA, write a kernel for CUDA and run it on GPU. |
You can even earn some money if you discover large enough prime numbers, EFF is giving prizes from $50K to $250K: https://www.eff.org/awards/coop |
There is a 100% mathematical test that will check if a number P is prime or composite, called AKS Primality Test. |
The concept is simple: given a number P, if all the coefficients of (x-1)^P - (x^P-1) are divisible by P, then P is a prime number, otherwise it is a composite number. |
For instance, given P = 3, would give the polynomial: |
(x-1)^3 - (x^3 - 1) |
= x^3 + 3x^2 - 3x - 1 - (x^3 - 1) |
= 3x^2 - 3x |
And the coefficients are both divisible by 3, therefore the number is prime. |
And example where P = 4, which is NOT a prime would yield: |
(x-1)^4 - (x^4-1) |
= x^4 - 4x^3 + 6x^2 - 4x + 1 - (x^4 - 1) |
= -4x^3 + 6x^2 - 4x |
And here we can see that the coefficients 6 is not divisible by 4, therefore it is NOT prime. |
The polynomial (x-1)^P will P+1 terms and can be found using combination. So, this test will run in O(n) runtime, so I don't know how useful this would be since you can simply iterate over i from 0 to p and test for the remainder. |
• 5 |
AKS is a very slow method in practice, not competitive with other known methods. The method you describe is not AKS but an opening lemma that is slower than unoptimized trial division (as you point out). – DanaJ Nov 29 '14 at 6:41 |
• hello @Kousha, what does the x stands for? in (x-1)^P - (x^P-1). do you have a sample code for this? in C++ for determining if the integer is prime or not? – kiLLua Oct 5 '16 at 7:59 |
• @kiLLua X is just a variable. It's the coefficient of X that determine whether or not the number is prime or not. And no I do not have the code. I don't recommend to actually use this method for determining if a number is prime or not. This is just a very cool mathematical behaviour of prime numbers, but otherwise ... |
Is your problem to decide whether a particular number is prime? Then you need a primality test (easy). Or do you need all primes up to a given number? In that case prime sieves are good (easy, but require memory). Or do you need the prime factors of a number? This would require factorization (difficult for large number... |
One clever and efficient way is to pre-compute tables of primes and keep them in a file using a bit-level encoding. The file is considered one long bit vector whereas bit n represents integer n. If n is prime, its bit is set to one and to zero otherwise. Lookup is very fast (you compute the byte offset and a bit mask) ... |
• A good primality test is competitive with main memory latency for prime tables that could reasonably fit, so I wouldn't use this unless it could fit into L2. – Charles Aug 19 '11 at 4:37 |
Rabin-Miller is a standard probabilistic primality test. (you run it K times and the input number is either definitely composite, or it is probably prime with probability of error 4-K. (a few hundred iterations and it's almost certainly telling you the truth) |
There is a non-probabilistic (deterministic) variant of Rabin Miller. |
The Great Internet Mersenne Prime Search (GIMPS) which has found the world's record for largest proven prime (274,207,281 - 1 as of June 2017), uses several algorithms, but these are primes in special forms. However the GIMPS page above does include some general deterministic primality tests. They appear to indicate th... |
It depends on your application. There are some considerations: |
• Do you need just the information whether a few numbers are prime, do you need all prime numbers up to a certain limit, or do you need (potentially) all prime numbers? |
• How big are the numbers you have to deal with? |
The Miller-Rabin and analogue tests are only faster than a sieve for numbers over a certain size (somewhere around a few million, I believe). Below that, using a trial division (if you just have a few numbers) or a sieve is faster. |
I will let you decide if it's the fastest or not. |
using System; |
Subsets and Splits
No community queries yet
The top public SQL queries from the community will appear here once available.