Binary tree construction, traversal, and release--writing data structures by itself

Directly on the code

The bitree.h file is as follows:

#ifndef _bitree_h_#define _bitree_h_typedef  char telemtype;typedef struct _bitnode{    telemtype data;    struct _bitnode *lchild,*rchild;                } Bitnode,*pbitnode;int bittree_creat (Bitnode **t); void Pre_order (Bitnode *t); void Mid_order (Bitnode *T); void Post_ Order (Bitnode *t); #endif

bittree.c files are as follows

/*************************** Time: 2014.12.16xiao_ping_ping compilation environment: dev-c++ 4.9.9.2 Content: Two fork tree construction, traversal, and release capabilities: Learn to write data structures ************ (1) scanf ("%c", &ch), and scanf ("%d", &ch), the difference being that the former is a one-time input, The latter need to enter a number after the carriage return (2) C language pointer as a function parameter, the function cannot change the value of the pointer, can only change the pointer to the content of the value (only with a level two pointer), C + + can be referenced by * (&AMP;P) to change the value of the parameter pointer inside the function (3) It is also impossible to implement a pointer (including a struct pointer) as a function parameter to its task within the function of the non-allocated space (but can complete the free operation), another solution is to initialize a pointer inside the function after the allocation of space, and then passed the form of the return value to the external pointer ******** /#include <string.h> #include <stdio.h> #include "bitree.h"/* Create a two-fork tree */int bittree     _creat (Bitnode **t)//c language functions cannot be changed inside the pointer as a parameter {char ch;          scanf ("%c", &ch);     *t = * (T)->lchild;         if (' 0 ' = = ch) {*t = NULL;       return 0;      } *t = (Bitnode *) malloc (sizeof (Bitnode));             if (NULL = = *t) {return-1;          } (*t)->data = ch;        Bittree_creat (& (*t)->lchild);                 Bittree_creat (& (*t)->rchild); return 1;} /* Pre-sequence Traversal binary tree */void PRE_order (Bitnode *t) {if (NULL = = T) {return;     } printf ("%c", t->data);      Pre_order (T->lchild);              Pre_order (T->rchild);    }/* Middle sequence Traversal binary tree */void mid_order (Bitnode *t) {if (NULL = = T) {return;      } mid_order (T->lchild);     printf ("%c", t->data);     Mid_order (T->rchild);    }/* post-traversal binary tree */void post_order (Bitnode *t) {if (NULL = = T) {return;      } post_order (T->lchild);         Post_order (T->rchild); printf ("%c", T->data);}            /* Free two fork tree */int free_btree (Bitnode *t) {if (NULL = = T) {return 0;    } free_btree (T->lchild);    Free_btree (T->rchild);         Free (T);  return 1;}

The test file test.c is as follows:

/*************************************************/#include <string.h> #include <stdio.h> #include < conio.h> #include "bitree.h" int main () {    pbitnode btree;    printf ("Create binary tree:\n");    Bittree_creat (&btree);        printf ("\ n pre-order:");    Pre_order (btree);    printf ("\ n sequence:");    Mid_order (btree);    printf ("N-post:");    Post_order (btree);        printf ("\ nthe binary Tree Destruction");    Free_btree (btree);         Getch ();    return 0;       }

The results of the operation are as follows:

Binary tree construction, traversal, and release--writing data structures by itself