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  1. import java.util.*;
  2. import java.io.*;
  3.  
  4. class Main {
  5.  
  6.  
  7. 	public static void main(String[] args) throws Exception{
  8. 		Scanner in = new Scanner(System.in);
  9. 		PrintWriter out = new PrintWriter(System.out, true);
  10.  
  11. 		while(in.hasNextInt()){
  12. 			int i = in.nextInt();
  13. 			int j = in.nextInt();
  14.  
  15. 			int from = Math.min(i,	j);
  16. 			int to = Math.max(i, j);
  17.  
  18. 			int max = 0;
  19.  
  20. 			for (int ii = from;ii<=to;ii++){
  21. 				max = Math.max(max, computeCycleLength(ii));
  22. 			}
  23.  
  24. 			out.printf("%d %d %d\n", i, j, max);
  25. 		}
  26.  
  27. 	}
  28.  
  29. 	private static int computeCycleLength(long n) {
  30.  
  31. 		if (n==1)
  32. 				return 1;
  33. 		if (n<_MaxValue && memo[(int)n] != 0)
  34. 			return memo[(int)n];
  35.  
  36. 		// computing length of collatz cycle 
  37. 		int len = 1 + computeCycleLength(nextCollatz(n));
  38.  
  39. 		// storing it in cache 
  40. 		if (n<_MaxValue)
  41. 			memo[(int)n] = len;
  42. 		return len;
  43. 	}
  44.  
  45.  
  46. 	private static int _MaxValue = 1000000;
  47. 	public static int[] memo = new int[_MaxValue];
  48.  
  49. 	public static long nextCollatz(long n){
  50.  
  51. 		if (n%2==0)
  52. 			return n/2;
  53. 		else 
  54. 			return n*3+1;
  55. 	}
  56.  
  57.  
  58. }
  59.  
Success #stdin #stdout 0.12s 380608KB
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https://ideone.com/ecGyT4
language:
Java (HotSpot 12)
created:
11 years ago
visibility:
public

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