Data structure algorithm (basic algorithm of tree)

The serialization and deserialization of a tree

1) serialization and deserialization of the two-fork tree; the use of a pre-order.

1  PackageCom.tree;2 3 Importjava.util.LinkedList;4 ImportJava.util.Queue;5 6 //serializes a two-pronged tree into a string;7 //and deserializes a string into a tree.8  Public classtreenode_serialization {9      Public Static voidMain (string[] args) {TenTreenode_serialization s =Newtreenode_serialization (); OneString str = "2!3!10!#!#!12!123!#!#!#!18!100!#!#!#!";//Pre-order ATreeNode node =S.pre_deserializationtreenode (str); - s.test (node); - System.out.println (); the System.out.println (S.pre_serializtreenode (node)); -     } -     //serializes a two-pronged tree into a string -      PublicString pre_serializtreenode (TreeNode tree) { +         if(Tree = =NULL) { -             return"#!"; +         } AString str = tree.val + "!"; atstr + =Pre_serializtreenode (tree.left); -str + =Pre_serializtreenode (tree.right); -         returnstr; -     } -     //deserializes a string into a tree;//deserialization of a pre-sequence traversal -      PublicTreeNode Pre_deserializationtreenode (String str) { instring[] Arrstr = Str.split ("!"); -Queue<string> qu =NewLinkedlist<string>(); to          for(String s:arrstr) { + Qu.add (s); -         } the         returnPre_deserializationtreenodecore (qu); *     } $     //Pre-sequence traversal deserialization. Panax Notoginseng     PrivateTreeNode Pre_deserializationtreenodecore (queue<string>qu) { -String str =Qu.poll (); theTreeNode tree =NewTreeNode (); +         if("#". Equals (str)) { A             return NULL; the         } +Tree.left =Pre_deserializationtreenodecore (qu); -Tree.val =integer.valueof (str); $Tree.right =Pre_deserializationtreenodecore (qu); $         returnTree; -     } -      Public voidTest (TreeNode tree) { the         if(Tree! =NULL) { - test (tree.left);WuyiSystem.out.print (Tree.val + ""); the test (tree.right); -         } Wu     } -}

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2) serialization and deserialization of the two-fork tree; A hierarchical traversal is used.

Second, the traversal of the tree (before and after the "recursive and non-recursive", hierarchical, showing the structure of the hierarchy traversal)

　　

Data structure algorithm (basic algorithm of tree)