删除偏斜堆的方法

我正在尝试创建偏斜的堆类，但是我在从堆中删除元素的ememove函数在代码的末尾有问题。逻辑似乎正确。合并其孩子。任何建议？

struct node{
    int key;
    node* left;
    node* right;
};
class skewHeap{
public:
    skewHeap(int k);
    ~skewHeap();
    skewHeap& operator=(const skewHeap&);
    node* merge(node* a,node* b);
    void remove(node* a,int k);
    void add(int k);
    void print(node*) const;
    node* getRoot();
private:
    node* root;
    void del(node* n){
        if(n == NULL) return;
        else{
        del(n->left);
        del(n->right);
        delete n;
        }
    }
    node* copy(node* n){
        if(n == NULL) return NULL;
        node* tmp = new node;
        tmp->key = n ->key;
        tmp->left = copy(n->left);
        tmp->right = copy(n->right);
                 return tmp;
    }

};
skewHeap::skewHeap(int k){
    root = new node;
    root->key = k;
    root->left = NULL;
    root->right = NULL;
}
skewHeap::~skewHeap(){
    del(root);
}
skewHeap& skewHeap::operator=(const skewHeap& n){
    if( this != &n){
        del(root);
        root = n.root;
        copy(root);
    }
    return *this;
}
node* skewHeap::merge(node* a,node* b){
    if(a == NULL) return b;
    if(b == NULL) return a;
    else {
        if(a->key > b->key){
            node* tmp = a;
            a = b;
            b = tmp;
        }
        node* tmp = a->right;
        a->right = a->left;
        a->left = merge(b,tmp);
    }
    return a;
}

void skewHeap::add(int k){
    node* p = new node;
    p->key = k;
    p->left = NULL;
    p->right = NULL;
    root = merge(root,p);
}
void skewHeap::print(node* n) const{
    if(n == NULL) return;
    else{
        print(n->left);
        cout<<n->key<<" ";
        print(n->right);
    }
}
node* skewHeap::getRoot(){
    return root;
}
void skewHeap::remove(node* n,int k){
    if( n == NULL) return;
    if(n->key == k)  {
        n = merge(n->left,n->right);
        return;
        }
    remove(n->left,k);
    remove(n->right,k);
}