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  1. class Node:
  2. def __init__(self, name=None, parent=None, available=True):
  3. self.name = name
  4. self.parent = parent
  5. self.available = available
  6. self.children = []
  7.  
  8. @property
  9. def next_sibling(self):
  10. """Return next node on the same level."""
  11. try:
  12. return self.parent.children[self.parent.children.index(self)+1]
  13. except (AttributeError, IndexError):
  14. return None
  15.  
  16. @property
  17. def next_node(self):
  18. """Return next available node using depth-first search."""
  19. def f(node):
  20. return node if node.available else node.next_node
  21.  
  22. if self.available and self.children:
  23. return f(self.children[0])
  24.  
  25. elif self.next_sibling:
  26. return f(self.next_sibling)
  27.  
  28. node = self
  29. while node.parent is not None:
  30. node = node.parent
  31. if node.next_sibling:
  32. return f(node.next_sibling)
  33.  
  34. return None
  35.  
  36.  
  37. def print_tree(node, only_available=False):
  38. todo = [node]
  39. while todo:
  40. node = todo.pop()
  41. if only_available and not node.available:
  42. continue
  43. todo.extend(reversed(node.children))
  44. print(node.name + (' (unavailable)' if not node.available else ''))
  45.  
  46.  
  47. def traverse(node):
  48. while True:
  49. print(node.name)
  50. node = node.next_node
  51. if not node:
  52. break
  53.  
  54.  
  55. grandparent = Node(name='grandparent')
  56. parent0 = Node(name=' parent0', parent=grandparent)
  57. parent1 = Node(name=' parent1', parent=grandparent)
  58. parent2 = Node(name=' parent2', parent=grandparent, available=False)
  59. parent3 = Node(name=' parent3', parent=grandparent)
  60. child0 = Node(name=' child0', parent=parent0, available=False)
  61. child1 = Node(name=' child1', parent=parent0, available=False)
  62. child2 = Node(name=' child2', parent=parent1, available=False)
  63. child3 = Node(name=' child3', parent=parent1)
  64. child4 = Node(name=' child4', parent=parent2)
  65. child5 = Node(name=' child5', parent=parent3)
  66. child6 = Node(name=' child6', parent=parent3, available=False)
  67. grandchild0 = Node(name=' grandchild0', parent=child0)
  68. grandchild1 = Node(name=' grandchild1', parent=child0)
  69. grandchild2 = Node(name=' grandchild2', parent=child3)
  70. grandparent.children = [parent0, parent1, parent2, parent3]
  71. parent0.children = [child0, child1]
  72. parent1.children = [child2, child3]
  73. parent2.children = [child4]
  74. parent3.children = [child5, child6]
  75. child0.children = [grandchild0, grandchild1]
  76. child3.children = [grandchild2]
  77. print('Full node tree:\n')
  78. print_tree(grandparent, only_available=False)
  79. print('\n\nGoal sequence:\n')
  80. print_tree(grandparent, only_available=True)
  81. print('\n\nTraverse using Node.next_node() method (must be equal to "Goal sequence"):\n')
  82. traverse(grandparent)
Success #stdin #stdout 0.02s 9120KB
stdin
Standard input is empty
stdout
Full node tree:

grandparent
    parent0
        child0 (unavailable)
            grandchild0
            grandchild1
        child1 (unavailable)
    parent1
        child2 (unavailable)
        child3
            grandchild2
    parent2 (unavailable)
        child4
    parent3
        child5
        child6 (unavailable)


Goal sequence:

grandparent
    parent0
    parent1
        child3
            grandchild2
    parent3
        child5


Traverse using Node.next_node() method (must be equal to "Goal sequence"):

grandparent
    parent0
    parent1
        child3
            grandchild2
    parent3
        child5