什么是树中的节点?

What is node in a tree?

根据wiki,树中的一切都是一个节点。

树中使用的术语

Root – The top node in a tree.
Parent – The converse notion of child.
Siblings – Nodes with the same parent.
Descendant – a node reachable by repeated proceeding from parent to child.
Ancestor – a node reachable by repeated proceeding from child to parent.
Leaf – a node with no children.
Internal node – a node with at least one child.
External node – a node with no children.
Degree – number of sub trees of a node.
Edge – connection between one node to another.
Path – a sequence of nodes and edges connecting a node with a descendant.
Level – The level of a node is defined by 1 + the number of connections between the node and the root.
Height of tree –The height of a tree is the number of edges on the longest downward path between the root and a leaf.
Height of node –The height of a node is the number of edges on the longest downward path between that node and a leaf.
Depth –The depth of a node is the number of edges from the node to the tree's root node.
Forest – A forest is a set of n ≥ 0 disjoint trees.

但是后来我从SAP中找到了下面的图片http://www.sapdesignguild.org/community/design/print_hierarchies2.asp

所以我的问题 - 将树中的根、叶、parents、children、兄弟姐妹称为节点是否正确?

是的。根是 "the root node." 一个 parent 是一个 "parent node." 叶子是一个 "leaf node." 树是由节点组成的。 root、parent、child、sibling、leaf等术语只是描述了节点之间的关系。

比如根节点没有parent。叶节点没有children。兄弟节点共享相同的 parent.