Question

我有一个八叉树，我必须删除它所搜索的节点的分支。该程序可以找到节点，但我很难删除它。当我创建一个Octree的对象并创建一些节点但我不删除它们时，析构函数就删除了八叉树：

Octree::~Octree()
{
clear(root);
}

void Octree::clear(node *node){
for (int i = 0; i < 8; i++)
    if (node->child[i])
        clear(node->child[i]);

delete node;
}

但是当我想用这种方法删除一个具体的节点时，

void Octree::deletebranch(int branch) {
node *n = search(branch);
if (n) {
    for (int i = 0; i < 8; i++) {
        if (n->child[i]) {
            delete n->child[i];
            n->child[i] = NULL;
        }
    }
    delete n;
    n = NULL;
}
else {
    printf("There is nothing to delete here");
}
}

析构函数调用后我得到了一个异常。抛出异常：读取访问冲突。节点是0x4。

我一步一步地调试，发现了一些奇怪的事情。当我创建节点时，我这样做：

        n = new node;
        n->value = xvalue;
        for (int i = 0; i < 8; i++)
            n->child[i] = NULL;

没关系，我设置了值，节点的值是xvalue，子节点是NULL。但是在用deletebranch（）方法删除了那个节点后，我的节点发生了这样的变化。

n 0x00500788 {value = 0 child = 0x0050078c {0x00000004 {value = ??? child = 0x00000008 {???，???，???，???，???，...}}，...}} Octree :: node * 值0 int
child 0x0050078c {0x00000004 {value = ??? child = 0x00000008 {???，???，???，???，???，???，???，???}}，0xfdfdfdfd {...}，...}八叉树:: node * [8]
[0] 0x00000004 {value = ??? child = 0x00000008 {???，???，???，???，???，???，???，???}} Octree :: node *
[1] 0xfdfdfdfd {value = ??? child = 0xfdfdfe01 {???，???，???，???，???，???，???，???}} Octree :: node *
[2] 0xdddddddd {value = ??? child = 0xdddddde1 {???，???，???，???，???，???，???，???}} Octree :: node *
[3] 0x29122f71 {value = ??? child = 0x29122f75 {???，???，???，???，???，???，???，???}} Octree :: node *
[4] 0x0000a9bd {value = ??? child = 0x0000a9c1 {???，???，???，???，???，???，???，???}} Octree :: node *
[5] 0x004d5228 {value = 5249384 child = 0x004d522c {0x005007a0 {value = 5067304 child = 0x005007a4 {0x004fe218 {...}，...}}，...}} Octree :: node *
[6] 0x004fe218 {value = 5244832 child = 0x004fe21c {0x004d00c4 {value = 5235224 child = 0x004d00c8 {0x00501968 {...}，...}}，...}} Octree :: node *
[7] 0xdddddddd {value = ??? child = 0xdddddde1 {???，???，???，???，???，???，???，???}} Octree :: node *
这个0x0043f818 {root = 0x005006b0 {value = 0 child = 0x005006b4 {0x00000000,0x00000000,0x00000000，...}}}八叉树*

我真的不明白为什么会这样，因为我删除它后从未更改过节点。而且我认为这就是我在析构函数中得到异常的原因。我该如何删除节点？也许尝试捕捉？

这是头文件：

class Octree
{ 
public:
struct node
{
    int value;
    node *child[8];
};

Octree();
~Octree();

void clear(node* node);
int convert(int sorszam);
node* searchandset(int dec, int value);
node *search(int dec);
node* step(node *node, int k);
void Print(node *n)const;
void put(int branch, int value);
void deletebranch(int branch);
node *root;
};

如何删除八叉树c ++的节点（节点为0x4。）

0 个答案: