树的子结构

/* 18 判断树的子结构： */
bool DoseTree1HasTree2(BinTree* root1, BinTree* root2)
{
    if (root2 == NULL)
        return true;
    if (root1 == NULL)
        return false;
    if (root1->m_nValue != root2->m_nValue)
        return false;
    return DoseTree1HasTree2(root1->m_pLeft, root2->m_pLeft) && DoseTree1HasTree2(root1->m_pRight, root2->m_pRight);
}

bool HasSubTree(BinTree* root1, BinTree* root2)
{
    bool res = false;

    if (root1 != NULL && root2 != NULL)
    {
        if (root1->m_nValue == root2->m_nValue)
            res = DoseTree1HasTree2(root1, root2);
        if (!res)
            HasSubTree(root1->m_pLeft, root2);
        if (!res)
            HasSubTree(root1->m_pRight, root2);
    }
    return res;
}