我有一个八叉树,我必须删除一个通过它的分支搜索的节点。该程序可以找到该节点,但我很难删除它。当我创建八叉树的对象并创建一些节点但不删除它们时,析构函数将删除八叉树:
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");
}
}
调用析构函数后出现异常。抛出异常:读取访问冲突。节点为 0x4。
我正在一步一步调试,我发现了一些奇怪的东西。当我创建一个节点时,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,节点的值为 xvalue,子节点为 NULL。但是在我使用 deletebranch() 方法删除该节点后,我的节点发生了这样的变化。
- n 0x00500788 {值=0 孩子=0x0050078c {0x00000004 {值=???child=0x00000008 {???, ???, ???, ???, ???, ...} }, ...} } Octree::node * value 0 int
- 孩子 0x0050078c {0x00000004 {值=???child=0x00000008 {???, ???, ???, ???, ???, ???, ???, ???} }, 0xfdfdfdfd {...}, ...} 八叉树::节点 *[8]
- [0] 0x00000004 {值=???child=0x00000008 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::node *
- [1] 0xfdfdfdfd {值=???child=0xfdfdfe01 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::node *
- [2] 0xdddddddd {值=???child=0xdddddde1 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::node *
- [3] 0x29122f71 {值=???child=0x29122f75 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::node *
- [4] 0x0000a9bd {值=???child=0x0000a9c1 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::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 {值=???child=0xdddddde1 {???, ???, ???, ???, ???, ???, ???, ???} } Octtree::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。我认为这就是为什么我在析构函数中得到了那个异常。我应该如何删除一个节点?也许尝试抓住?
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;
};