C語言實現二叉樹的遍歷

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


typedef  char   TElemType ;

typedef struct TNode
{
    TElemType data;
    struct TNode *lchild , *rchild;
}BiTNode , *BiTree;

int creatTree(BiTree *root) //遞歸創建二叉樹
{
    char ch;
    scanf("%c" , &ch);
    if(ch == '#')
    {
        (*root) = NULL;
    }
    else
    {
        if(!((*root) = (BiTNode *)malloc(sizeof(BiTNode))))
        {
            printf("malloc error!\n");
            return -1;
        }
        (*root)->data = ch;
        creatTree(&((*root)->lchild));
        creatTree(&((*root)->rchild));
    }

    return 0;
}
void preOrderTraverse(BiTree tree)  //遞歸前序遍歷
{

    if(tree)
    {
        printf("%c", tree->data);
        preOrderTraverse(tree->lchild);
        preOrderTraverse(tree->rchild);

    }

    return ;
}
void inOrderTraverse(BiTree tree)   //遞歸中序遍歷
{
    if(tree)
    {
        inOrderTraverse(tree->lchild);
        printf("%c", tree->data);
        inOrderTraverse(tree->rchild);
    }
    return ;
}

void lastOrderTraverse(BiTree tree) //遞歸後序遍歷
{
    if(tree)
    {
        lastOrderTraverse(tree->lchild);
        lastOrderTraverse(tree->rchild);
        printf("%c", tree->data);
    }
    return ;
}
int main(int argc , char **argv)
{
    BiTree tree ;
    creatTree(&tree);
    printf("\n*********先序遍歷*********\n");
    preOrderTraverse(tree);
    printf("\n*********中序遍歷*********\n");
    inOrderTraverse(tree);
    printf("\n*********後序遍歷*********\n");
    lastOrderTraverse(tree);
    printf("\n");

    return 0;
}