二叉树的建立

定义树的结构：

typedef int ElemType;

struct BinaryTreeNode
{
    ElemType m_nValue;//结点值
    BinaryTreeNode *m_pLeft;//左节点地址
    BinaryTreeNode *m_pRight;//右节点地址
};

将二叉树构建成一个完整的，若不存在的节点用字符'#'代替，

BinaryTreeNode * CreateTree(BinaryTreeNode *bTree)
{
    int input;
    scanf("%d",&input);            //按先序建立二叉树
    if(input == ‘#’)
    {
        bTree = NULL;    //置为NULL后结束
        return bTree;    
    }
    bTree = (BinaryTreeNode *)malloc(sizeof(BinaryTreeNode));
    bTree ->m_nValue = input;
    bTree->m_pLeft = CreateTree(bTree->m_pLeft);
    bTree->m_pRight = CreateTree(bTree->m_pRight);
    return bTree;
}