n元树结构的析构函数

Question

I have the following code:

const int MAXCHILD = 10;

struct Node {
    Node *child[10];

    Node();
    void deleteNode(Node *n);
    ~Node();
};

Node::Node() {
    for(int i=0; i<MAXCHILD; i++) {
        child[i] = NULL;
    }
}

void Node::deleteNode(Node *n) {
    if(n == NULL) {
        return;
    } else {
        for(int i=0; i<MAXCHILD; i++) {
            deleteNode(n->child[i]);
        }

        for(int i=0; i<MAXCHILD; i++) {
            n->child[i] = NULL;
        }
    }

    n = NULL;
}

Node::~Node() {
    Node *n = this;
    deleteNode(n);
}

int main() {
    Node *n = new Node();

    ...

    delete n;
    n = NULL;

    return 0;
}

This is what I've tried.
I don't get any critical errors while compiling/testing but when I test for memory leaks with Valgrind, it shows I'm constantly making memory leaks.

I'm aware there are many flaws in my destructor; what would be the problem?
Thank you in advance!

Answer 1

The memory leak is caused by your never deallocating the children.
(Setting the pointers to NULL isn't enough.)

Your destructor could be as simple as this:

Node::~Node() {
    for(int i=0; i<MAXCHILD; i++) {
        delete child[i];
        child[i] = nullptr;
    }
}

Answer 2

The other reason of memory leak also can be recursive generation or construction of children nodes. It will be better if you change child data field inside structure and manage it in a different way like carrying it somehow inside of the constructor or linking childs and parent externally. Try it may be it will get you out of memory leak