我有一个像这样的不寻常的树数组：

[[0, 1], [1, 2], [2, 3], [2, 4], [2, 5], [5, 6], 
 [4, 6], [3, 6], [0, 7], [7, 6], [8, 9], [9, 6]]

数组的每个元素都是一对,这意味着第二个元素是第一个的跟随者,例如：

[0, 1] - 0 is followed by 1
[1, 2] - 1 is followed by 2

我试图提取这样的数组：

0 1 2 3 6    
0 1 2 4 6    
0 1 2 5 6
0 7 6
8 9 6

我无法编写强大的遍历来提取所有可能的路径.我怎么能用Python做到这一点？

解决方法:

干得好.不是地球上最好的代码,但它有效：

inputValues = [[0, 1], [1, 2], [2, 3], [2, 4], [2, 5], [5, 6], [4, 6], [3, 6], [0, 7], [7, 6], [8, 9], [9, 6]]

tree = {}
numberOfChildren = {}
for (f, t) in inputValues:
  if not tree.has_key(f):
    tree[f] = []
  tree[f].append(t)
  if not numberOfChildren.has_key(t):
    numberOfChildren[t] = 0
  numberOfChildren[t] += 1

roots = [c for c in tree if c not in numberOfChildren]
permutations = []

def findPermutations(node, currentList):
  global tree
  global permutations
  if not tree.has_key(node):
    permutations.append(currentList)
    return
  for child in tree[node]:
    l = list()
    l.extend(currentList)
    l.append(child)
    findPermutations(child, l)

for r in roots:
  findPermutations(r, [r])

print permutations