二叉树建立（队列）

struct Bitnode
{
    struct Bitnode *left,*right;
    int val;
};
typedef struct Bitnode Bitnode;
Bitnode *CreatBitree_level()
{
    Bitnode *Q[100];
    int front=1,rear=0,n;
    Bitnode *root=NULL,*s;
    while(scanf("%d",&n),n!=-1)
    {
        if(n==0) s=NULL;
        else
        {
            s=(Bitnode*)malloc(sizeof(Bitnode));
            s->val=n;
            s->left=NULL;
            s->right=NULL;
        }
        Q[++rear]=s;
        if(rear==1) root=s;
        else
        {
            if(s&&Q[front])
            {
                if(rear%2==0) Q[front]->left=s;
                else Q[front]->right=s;
            }
            if(rear%2==1) front++;
        }
    }
    return root;
}
int depth(Bitnode *root)
{
    if(root==NULL) return 0;
    int x,y;
    x=depth(root->left);
    y=depth(root->right);
    return x>y?x+1:y+1;
}