fork(1) download 
  1. /* package whatever; // don't place package name! */
  2.  
  3. import java.util.*;
  4. import java.lang.*;
  5. import java.io.*;
  6. import java.util.stream.*;
  7.  
  8. /* Name of the class has to be "Main" only if the class is public. */
  9. class Ideone
  10. {
  11. 	static class Tree<T> {
  12. 		List<Tree<T>> children = new ArrayList<>();
  13. 		T rootValue;
  14.  
  15. 		Tree(T rootValue) {
  16. 			this.rootValue = rootValue;
  17. 		}
  18.  
  19. 		Tree<T> add(Tree<T>... children) {
  20. 			this.children.addAll(Arrays.asList(children));
  21. 			return this;
  22. 		}
  23.  
  24. 		public String toIndentedString() {
  25. 			return "\n" + rootValue + children.stream()
  26. 					.map(Tree::toIndentedString)
  27. 					.map(s -> s.substring(0, s.length() - 1))
  28. 					.map(s -> s.replaceAll("\n", "\n  "))
  29. 					.collect(Collectors.joining())
  30. 					+ "\n";
  31. 		}
  32. 	}
  33.  
  34. 	public static void main(String[] args) {
  35. 		Tree<String> tree =
  36. 			new Tree<>("food")
  37. 				.add(new Tree<>("meat")
  38. 					.add(new Tree<>("fish")
  39. 						.add(new Tree<>("salmon"))
  40. 						.add(new Tree<>("cod"))
  41. 						.add(new Tree<>("tuna"))
  42. 						.add(new Tree<>("shark"))
  43. 					)
  44. 				)
  45. 				.add(new Tree<>("fruit"))
  46. 				.add(new Tree<>("vegetable"));
  47.  
  48. 		System.out.println("[" + tree.toIndentedString() + "]");
  49. 	}
  50. }
Success #stdin #stdout 0.13s 4386816KB
comments (?)
stdin 
Standard input is empty
stdout 
[
food
  meat
    fish
      salmon
      cod
      tuna
      shark
  fruit
  vegetable
]
https://ideone.com/YYUdaJ
language:
Java (HotSpot 12)
created:
8 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!