- List of prime numbers to 2000000 generator#
- List of prime numbers to 2000000 update#
- List of prime numbers to 2000000 code#
IsPrime() is designed specifically for being called with increasing input n. prevents duplicate primes from being added
![list of prime numbers to 2000000 list of prime numbers to 2000000](https://mathondemand.com/wp-content/uploads/2021/03/Prime-Factorization-of-a-Composite-Number-1024x311.png)
known prime and sqrt(n) are factors of n I strongly suspect that this approach will be more than fast enough for your needs. If your goal is to compute the sum of the first however many prime numbers, then this is easy: build a list of prime numbers, checking each new candidate against the numbers already in your list. But to check whether a number is prime, you only need to check its divisibility by prime numbers. You're iterating over all numbers from 2 to n. This change, by itself, should dramatically speed up your program, because most numbers have small divisors, and so most numbers will only run that loop a few times.Īnother easy speedup is to limit the numbers you loop over. For one thing, in the loop in isPrime, when number % i = 0, you should return false rather than incrementing a variable and checking it later.
List of prime numbers to 2000000 code#
(It sounds like you're trying to solve a given problem from a course or code challenge.)īut even with the algorithm you're using, there are easy ways to speed it up. In order to know what algorithm is right for your use case, we would need to know what your use case is. There are many algorithms for determining whether a number is prime, and there is a tradeoff between the complexity of the algorithm and the efficiency for large numbers. rev fL ) |> List.If you have to handle numbers as large as 2,000,000, then this is not the right way to solve the problem. Printfn "The first 20 anti-primes are :-" for (_,g ) in ( List. takeWhile ( fun (_,_,n ) ->n fE n (fG g ) ) ( seq ) fI ) |> List.
List of prime numbers to 2000000 generator#
This task uses Extensible Prime Generator (F#) ( setf facts (list- length (factors i ) ) ) (format t "The first 20 anti-primes are :~%" ) (multiple-value-bind (quotient remainder ) (floor n factor ) (remove-duplicates (nreconc lows highs ) ) ) ( do ( (limit ( 1+ (isqrt n ) ) ) (factor 1 ( 1+ factor ) ) ) Ĭommon Lisp ( defun factors (n &aux (lows ' ( ) ) (highs ' ( ) ) ) * COBOL solution to Anti-primes challangeĠ1 OUT-HDR PIC X ( 23 ) VALUE 'SEQ ANTI-PRIME FACTORS'. While antiPrimeCount maxDivisors then beginĮnd while_antiPrimeCoiunt_lt_maxAntiPrime Integer maxAntiPrime, antiPrimeCount, maxDivisors, n While ( p * p ) 1 then total := total * 2 Integer procedure divisor_count( integer value v ) begin % calculates the number of divisors of v % % find some anti-primes - numbers with more factors than the numbers %
![list of prime numbers to 2000000 list of prime numbers to 2000000](https://slideplayer.com/slide/14708684/90/images/4/Sample+prime+numbers+List+of+Primes+up+to+4483.jpg)
Mov bx ,nbuf Convert current number to ASCIIĬmp cl ,amount Do we need any more antiprimes?ĭb '.' Placeholder for decimal output
![list of prime numbers to 2000000 list of prime numbers to 2000000](https://i0.wp.com/edusaksham.com/upload/media/589658917_2020-09-16.jpg)
List of prime numbers to 2000000 update#
Mov ch, bl Update maximum amount of factors Inc cx If so, increment the amount of antiprimes seen
![list of prime numbers to 2000000 list of prime numbers to 2000000](https://upload.wikimedia.org/wikipedia/commons/b/b9/Sieve_of_Eratosthenes_animation.gif)
test : mov ax, si Test current candidate Xor cx, cx CH = max # of factors, CL = # of antiprimes Output: 1 2 4 6 12 24 36 48 60 120 1 5040 7560 8086 Assembly puts : equ 9 MS-DOS print string syscallĪmount : equ 20 Amount of antiprimes to find