计算二叉树深度

思想：先求左右子树的深度，取二者较大加1就是树的深度

int getTreeDeep(BitNode* t)
{
int deep = 0;
if (t)
{
int ldeep = getTreeDeep(t->lchild);
int rdeep = getTreeDeep(t->rchild);
deep = ldeep?rdeep:ldeep+1:rdeep+1;
}
return deep;
}