Template:Task: Difference between revisions
Content added Content deleted
No edit summary |
No edit summary |
||
| Line 21: | Line 21: | ||
<pre> |
<pre> |
||
> Search Size: 1000 |
> Search Size: 1000 |
||
> 35 twin prime pairs. |
|||
</pre> |
|||
=={{header|Java}}== |
|||
<lang java> |
|||
BigInteger Method: |
|||
import java.math.BigInteger; |
|||
import java.util.Scanner; |
|||
public class twinPrimes { |
|||
public static void main(String[] args) { |
|||
Scanner input = new Scanner(System.in); |
|||
System.out.println("Search Size: "); |
|||
BigInteger max = input.nextBigInteger(); |
|||
int counter = 0; |
|||
for(BigInteger x = new BigInteger("3"); x.compareTo(max) <= 0; x = x.add(BigInteger.ONE)){ |
|||
BigInteger sqrtNum = x.sqrt().add(BigInteger.ONE); |
|||
if(x.add(BigInteger.TWO).compareTo(max) <= 0) { |
|||
counter += findPrime(x.add(BigInteger.TWO), x.add(BigInteger.TWO).sqrt().add(BigInteger.ONE)) && findPrime(x, sqrtNum) ? 1 : 0; |
|||
} |
|||
} |
|||
System.out.println(counter + " twin prime pairs."); |
|||
} |
|||
public static boolean findPrime(BigInteger x, BigInteger sqrtNum){ |
|||
for(BigInteger divisor = BigInteger.TWO; divisor.compareTo(sqrtNum) <= 0; divisor = divisor.add(BigInteger.ONE)){ |
|||
if(x.remainder(divisor).compareTo(BigInteger.ZERO) == 0){ |
|||
return false; |
|||
} |
|||
} |
|||
return true; |
|||
} |
|||
} |
|||
</lang> |
|||
<pre> |
|||
> Search Size: |
|||
> 100 |
|||
> 8 twin prime pairs. |
|||
</pre> |
|||
<pre> |
|||
> Search Size: |
|||
> 1000 |
|||
> 35 twin prime pairs. |
> 35 twin prime pairs. |
||
</pre> |
</pre> |
||
Revision as of 05:35, 26 July 2020
You are encouraged to solve this task according to the task description, using any language you may know.
You are encouraged to solve this task according to the task description, using any language you may know.
Template loop detected: Template:Task A twin prime is a pair of natural numbers P1 and P2 that satisfy the following:
1. P1 and P2 are primes
2. P1 + 2 = P2
Write a program that displays the number of twin primes that can be found under a user-inputted number.
Examples below:
- Output:
> Search Size: 100 > 8 twin prime pairs.
> Search Size: 1000 > 35 twin prime pairs.
A twin prime is a pair of natural numbers P1 and P2 that satisfy the following:
1. P1 and P2 are primes
2. P1 + 2 = P2
Write a program that displays the number of twin primes that can be found under a user-inputted number.
Examples below:
- Output:
> Search Size: 100 > 8 twin prime pairs.
> Search Size: 1000 > 35 twin prime pairs.