Question

所以我正在尝试编写一个返回新制作的Huffman树的函数，该函数在列表中找到两个最小的频率然后删除它们（remove_smallest）然后使它们成为新的treeNode（root）的子节点再次将它插入列表中（采用霍夫曼树的风格）并完成所有操作，直到列表中剩下1个元素。在第二次调用remove_smallest函数之后，我的程序似乎正在崩溃。 remove_smallest函数返回列表中最小的treeNode它应该继续运行，直到剩下一个元素。我哪里错了？我为什么会出现分段错误？正如我所提到的，在两次调用remove_smallest之后，它似乎正在崩溃。

我是否取消引用指向随机内存的指针？或设置不正确的指针？

感谢任何帮助。谢谢。

代码：

typedef TreeNode* Element;
typedef Frequency* TreeElement;

struct TreeNode {

  TreeElement data; //stores a pointer to the data in this tree node
  TreeNode *left; //reference to the left child tree
  TreeNode *right; //reference to the right child tree

};

struct ListNode {
  Element data;  // stores a pointer to data in node
  ListNode *next; // reference to next node in list
};

struct List {
   ListNode *head;  // reference to the first node in the list
   int numElements; // the number of nodes in the list
};

struct HuffmanTree {
  TreeNode *root;
};

struct FrequencyList {
  List *freqs;
};

struct Frequency {
  char data; // the character being represented
  int count; // the number of occurrences of the character
};

    HuffmanTree *createHuffmanTree(FrequencyList *frequencies) {

    List * newList = new List;
    newList = frequencies->freqs;

    TreeNode * newTree1;
    TreeNode * newTree2;
    TreeNode * root = new TreeNode;


        while (frequencies->freqs->numElements != 1) {

            newTree1 = remove_smallest(frequencies); // removes and returns   smallest treeNode from list
            newTree2 = remove_smallest(frequencies);
            root->data->count = newTree1->data->count + newTree2->data->count; 
            root->left = newTree1;
            root->right = newTree2;

            insert(newList, root);  // inserts back into list

        }

        HuffmanTree * newHuffmanTree = new HuffmanTree;
        newHuffmanTree->root = root;

    return newHuffmanTree;

}

Answer 1

分段错误是由于尝试访问不存在的内存而引起的。对于不熟悉C / C ++的人来说，这是一个非常常见的错误。我会仔细检查你的所有指针，并确保你试图访问你想要的信息（地址/价值）。

为什么我的指针会出现分段错误？

1 个答案: