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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. 	static char[] pool = new char[]{'1', '2', '3'};
  11.  
  12. 	public static void buildStrings(char[] root, int length)
  13. 	{
  14. 		// allocate an array to hold our counts:
  15. 		int[] pos = new int[length];
  16. 		char[] combo = new char[length];
  17. 		for(int i = 0; i < length; i++)
  18. 		    combo[i] = root[0];
  19.  
  20. 		while(true)
  21. 		{
  22. 			// output the current combinations:
  23. 			System.out.println(String.valueOf(combo));
  24.  
  25. 			// move on to the next combination:
  26. 			int place = length - 1;
  27. 			while(place >= 0)
  28. 			{
  29. 				if(++pos[place] == root.length)
  30. 				{
  31. 					pos[place] = 0;
  32. 					combo[place] = root[0];
  33. 					place--;
  34. 				}
  35. 				else
  36. 				{
  37. 					combo[place] = root[pos[place]];
  38. 					break;
  39. 				}
  40. 			}
  41. 			if(place < 0)
  42. 			    break;
  43. 		}
  44. 	}
  45.  
  46. 	public static void main (String[] args) throws java.lang.Exception
  47. 	{
  48. 		// your code goes here
  49. 		buildStrings(pool, 2);
  50. 	}
  51. }
Success #stdin #stdout 0.1s 320256KB
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https://ideone.com/Hgm5iL
language:
Java (HotSpot 12)
created:
9 years ago
visibility:
secret

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