C语言关于二叉查找树的插入

Question

 typedef struct binary_tree_
{
    int data;
    struct binary_tree_ *left;
    struct binary_tree_ *right;
}binary_tree;  //这里binary_tree = struct binary_tree_



binary_tree* create_tree(int data)  //创建一个根节点 
{
    binary_tree* root=NULL;
    root=(binary_tree*)malloc(sizeof(struct binary_tree_));
    root->data=data;
    return root;
} 



binary_tree* insert(int data,binary_tree *T)  
{
    if(T==NULL)
    {
        T=(binary_tree*)malloc(sizeof(struct binary_tree_));
        T->data=data;
        T->left=NULL;
        T->right=NULL;  
    }
    else if(data<T->data)
        T->left=insert(data,T->left);   
    else if(data>T->data)
        T->right=insert(data,T->right);
    return T;   
}



int main(void)
{
    binary_tree *root;
    binary_tree *root1;
    root=create_tree(3);
    root1=insert(2,root);
    printf("%d",root1->data);
}

这是我自己写的关于二叉查找树的插入代码。求解大神为什么我一运行就崩溃。。。

Answer 1

创建根节点时出错，没有为左右节点赋初值，导致在插入时无法申请空间，程序崩溃

binary_tree* create_tree(int data)
{
    binary_tree* root=NULL;
    root=(binary_tree*)malloc(sizeof(struct binary_tree_));
    root->data=data;
        //加上下面两行
      root->left=NULL;
      root->right=NULL;
    return root;
}