二叉树构造与遍历

#include <stdio.h>
#include <stdlib.h>

struct biTree 
{
    char data ;
    struct biTree *lchild ;
    struct biTree *rchild ;        
};

typedef struct biTree BiTree;

void CreateBiTree( BiTree **T )//构造二叉树
{
char ch[2];
scanf( "%s", ch );

if( ch[0] == '#' )
*T = 0;
else
{
*T = (BiTree *)malloc( sizeof(BiTree) );
if( !(*T) )
exit( 1 );
(*T)->data = ch[0];

CreateBiTree( &(*T)->lchild );
CreateBiTree( &(*T)->rchild );
}
}

void PreOrderTraverse( BiTree* T )//前序
{
if( !T )
return ;

printf( "%c", T->data );
PreOrderTraverse( T->lchild );
PreOrderTraverse( T->rchild );
}

void InOrderTraverse( BiTree* T )//中序
{
if( !T )
return ;

InOrderTraverse( T->lchild );
printf( "%c", T->data );
InOrderTraverse( T->rchild );
}

void PostOrderTraverse( BiTree* T )//后序
{
if( !T )
return ;

PostOrderTraverse( T->lchild );
PostOrderTraverse( T->rchild );
printf( "%c", T->data );
}

void InOrder(BiTree* b)//非递归中序
{
BiTree *stack[100], *p;
int top = -1;
if (b != NULL)
{
p = b;
while (top > -1 || p != NULL)
{
while (p != NULL)//扫描p的所有左节点并入栈
{
top++;
stack[top] = p;
p = p->lchild;
}
if (top > -1)
{
p = stack[top];//出栈并访问该节点
top--;
printf("%c", p->data);
p = p->rchild;//扫描p的右孩子
}
}

printf("\n");
}
}

int main( void )
{
BiTree *T;

CreateBiTree( &T );

printf( "前序: " );
PreOrderTraverse( T );

printf( "\n中序: " );
InOrderTraverse( T );

printf( "\n后序: " );
PostOrderTraverse( T );

printf( "\n非递归中序: " );
InOrder( T );

printf( "\n" );
return 0;

}