如果给我两个节点和树的根。如何找到两个节点的共同祖先?
答案 0 :(得分:0)
您可以遵循此方法 在访谈中,这是一个常见的编程问题,您可以轻松地在interview sites
当从上到下遍历二进制搜索树时,我们遇到的第一个节点n的值在n1和n2之间,即n1
答案 1 :(得分:0)
嗨,这是我发现对LCA有用的python实现: -
class BST(object):
def __init__(self, val=None, right=None, left=None):
self.val = val
self.right = right
self.left = left
return None
def __nonzero__(self):
return self.val is not None
def insert(self, item):
if not self:
self.val = item
elif item < self.val:
if self.left:
return self.left.insert(item)
else:
self.left = BST(val=item)
elif item > self.val:
if self.right:
return self.right.insert(item)
else:
self.right = BST(val=item)
return None
def lca(self, m, n):
if n < self.val:
return self.left.lca(m, n)
elif m > self.val:
return self.right.lca(m, n)
else:
return self.val
if __name__ == "__main__":
b = BST()
for k in [8, 3, 10, 1, 6, 14, 4, 7, 13]:
b.insert(k)
for pair in [(4, 7), (4, 10), (1, 4), (1, 3), (3, 6)]:
print b.lca(*pair)