二叉树的基本定义和遍历

二叉树的基本定义和遍历：



#include<iostream>

using namespace std;

template <class T>

struct TreeNode {

       Tdata;

       TreeNode<T>*left;

       TreeNode<T>*right;

       TreeNode(constT &data=0)

              :data(data)

              ,left(NULL)

              ,right(NULL)

       {}

};

template <class T>

class BinaryTree {

       typedefTreeNode<T> Node;

private:

       Node*root;

private:

       Node*CreateTree(const T *arr, const int &len, const T &inval, int &i)

       {

              Node*cur = NULL;

              if(arr[i] == inval || i >= len)

              {

                     returncur;

              }

              cur= new Node(arr[i]);

              cur->left= CreateTree(arr, len,inval, ++i);

              cur->right= CreateTree(arr, len,inval, ++i);

              returncur;

       }

       voidpreorder(Node *cur)

       {

              if(cur == NULL)

              {

                     return;

              }

              cout<< cur->data << " ";

              preorder(cur->left);

              preorder(cur->right);

       }

       voidinorder(Node *cur)

       {

              if(cur == NULL)

              {

                     return;

              }

              inorder(cur->left);

              cout<< cur->data << " ";

              inorder(cur->right);

       }

       voidlastorder(Node *cur)

       {

              if(cur == NULL)

              {

                     return;

              }

              lastorder(cur->left);

              lastorder(cur->right);

              cout<< cur->data << " ";

       }

public:

       BinaryTree()

              :root(NULL)

       {}

       BinaryTree(constT *arr,const int &len,const T &inval)

       {

              inti = 0;

              root= CreateTree(arr, len, inval, i);

       }

       void_preorder()//前序遍历

       {

              preorder(root);

       }

       void_inorder()//中序遍历

       {

              inorder(root);

       }

       void_lastorder()//后序遍历

       {

              lastorder(root);

       }

4000
};

void testTree()

{

       intarr[] = { 25,56,17,'#','#',26,'#','#',15,32,89,'#','#',66,};

       BinaryTree<int>Tree(arr,sizeof(arr)/sizeof(arr[0]),'#');

       Tree._preorder();   cout << endl;

       Tree._inorder();     cout << endl;

       Tree._lastorder();   cout << endl;

}

int main()

{

       testTree();

   return 0;

}