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  1. import java.util.Random;
  2.  
  3. public class Main {
  4.  
  5. 	public static long seed;
  6. 	public static void main(String[] args)
  7. 	{
  8. 		Random r = new Random(123456789);
  9. 		long l = r.nextLong(); // первое случаное число
  10.  
  11. 		long oldSeedPart = (l >>> 32) << 16;
  12. 		long lastPart = l & 0xffffffffL;
  13. 		if ((int) lastPart < 0)
  14. 			oldSeedPart += (1L << 16);
  15. 		long i;
  16. 		for (i = 0; i < (1 << 16); ++i)
  17. 		{
  18. 			long oldSeed = oldSeedPart + i;
  19. 			long newSeed = (oldSeed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1);
  20. 			int rnd = (int)(newSeed >>> 16);
  21. 			if (rnd == (int) lastPart)
  22. 				break;
  23. 		}
  24. 		long oldSeed = oldSeedPart + i;
  25. 		oldSeed = (oldSeed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1);
  26. 		seed = oldSeed; // нашли текущий seed
  27.  
  28. 		System.out.println(Long.toHexString(nextLong())); // второе предсказанное случаное число
  29. 		System.out.println(Long.toHexString(r.nextLong())); // второе случаное число
  30. 	}
  31.  
  32. 	public static long nextLong() {
  33. 		return ((long)next(32) << 32) + next(32);
  34. 	}
  35.  
  36. 	public static int next(int bits) {
  37. 		seed = (seed * 0x5DEECE66DL + 0xBL) & ((1L << 48) - 1);
  38. 		int result = (int)(seed >>> (48 - bits));
  39. 		return result;
  40. 	}
  41. }
  42.  
Success #stdin #stdout 0.07s 380224KB
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74facac7413f22b0
74facac7413f22b0
https://ideone.com/lbCeca
language:
Java (HotSpot 12)
created:
9 years ago
visibility:
public

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