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  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6.  
  7. /* Name of the class has to be "Main" only if the class is public. */
  8. class Ideone
  9. {
  10. 	public static void main (String[] args) throws java.lang.Exception
  11. 	{
  12.         System.out.println(generate(50));
  13. 	}
  14.  
  15.     static ArrayList<Integer> generate(int n)
  16.     {
  17.         ArrayList<Integer> multiples = new ArrayList<>(), primes=new ArrayList<>(n);
  18.         primes.add(2);
  19.         multiples.add(2);
  20.         for (int candidate = 3;
  21.              primes.size() < n;
  22.              candidate += 2
  23.                 ) {
  24.             if (isPrime(candidate,multiples, primes))
  25.                 primes.add(candidate);
  26.         }
  27.         return primes;
  28.     }
  29.  
  30.     static boolean isPrime(int candidate, ArrayList<Integer> multiples, ArrayList<Integer> primes)
  31.     {
  32.         int nextPrime = primes.get(multiples.size()-1);
  33.         if (candidate == nextPrime * nextPrime) {
  34.             multiples.add(candidate);
  35.             return false;
  36.         }
  37.         for (int n = 1; n < multiples.size(); n++) {
  38.             int multiple = multiples.get(n);
  39.             while (multiple < candidate)
  40.                 multiple += 2 * primes.get(n);
  41.             multiples.set(n, multiple);
  42.             if (candidate == multiple)
  43.                 return false;
  44.         }
  45.         return true;
  46.     }
  47.  
  48. }
Success #stdin #stdout 0.06s 32464KB
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stdin
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Standard input is empty
stdout
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[2, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39, 41, 43, 45, 47, 49, 51, 53, 55, 57, 59, 61, 63, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99]
https://ideone.com/EpdmTi
language:
Java (HotSpot 12)
created:
6 years ago
visibility:
public

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