#include

"

iostream

"

#include

"

stdlib.h

"

using

namespace

std;

struct

tree

{

int

data;

struct

tree

*

left;

struct

tree

*

right;

};

typedef

struct

tree treenode;

typedef treenode

*

btree;

/*

------插入二叉树的结点-------

*/

btree insertnode(btree root,

int

value)

{

btree newnode;

btree current;

btree back;

/*

---创建新结点内存---

*/

newnode

=

(btree)malloc(

sizeof

(treenode));

newnode

->

data

=

value;

newnode

->

right

=

NULL;

newnode

->

left

=

NULL;

if

(root

==

NULL)

{

return

newnode;

}

else

{

current

=

root;

while

(current

!=

NULL)

{

back

=

current;

if

(current

->

data

>

value)

current

=

current

->

left;

else

current

=

current

->

right;

}

if

(back

->

data

>

value)

back

->

left

=

newnode;

else

back

->

right

=

newnode;

}

return

root;

}

/*

------创建二叉树--------

*/

btree createbtree(

int

*

data,

int

len)

{

btree root

=

NULL;

int

i;

for

(i

=

0

;i

<

len;i

++

)

root

=

insertnode(root,data[i]);

return

root;

}

/*

-----中序遍历------

*/

void

inorder( btree ptr)

{

if

(ptr

!=

NULL)

{

inorder(ptr

->

left);

printf(

"

[%2d]\n

"

,ptr

->

data);

inorder(ptr

->

right);

}

}

/*

-----------------------

*/

/*

--------前序遍历-------

*/

void

preorder(btree ptr)

{

if

(ptr

!=

NULL)

{

printf(

"

[%2d]\n

"

,ptr

->

data);

inorder(ptr

->

left);

inorder(ptr

->

right);

}

}

/*

-----------------------------

*/

/*

------后序遍历--------

*/

void

postorder(btree ptr)

{

if

(ptr

!=

NULL)

{

inorder(ptr

->

left);

inorder(ptr

->

right);

printf(

"

[%2d]\n

"

,ptr

->

data);

}

}

/*

---------------------------

*/

/*

---------主程序-----

*/

int

main()

{

btree root

=

NULL;

int

data[

9

]

=

{

5

,

6

,

4

,

8

,

2

,

3

,

7

,

1

,

9

};

root

=

createbtree(data,

9

);

printf(

"

树的结点内容：\n

"

);

inorder(root);

cout

<<

endl;

preorder(root);

cout

<<

endl;

postorder(root);

cout

<<

endl;

}