The standard definition of a tree: a finite set containing n (n>0) nodes.
1. Each element in the set is called a node (Node)
2. There is a special node called Root
3. The node ele
The standard definition of a tree: a finite set containing n (n>0) nodes.
1. Each element in the set is called a node (Node)
2. There is a special node called Root
3. The node ele