已知二叉树结点的定义如下： typedef struct Node{ DataType data; struct Node *LChild; struct Node *Rchild; }BiTNode, *BiTree; 若用二叉链表作为二叉树的存储表示，请设计代码求二叉树中度为 1 的结点个数。

好的，这个代码有一些问题： 1. `BiTree root` 在 `createTree` 函数中作为参数传入时，应该改为 `&root`，因为要修改这个指针变量指向的地址的值。 2. 函数名拼写错误，应该是 `PreOrder`， `InOrder` 和 `PostOrder`。 3. 在 `main` 函数中，调用函数时应该传入参数，即 `PreOrder(root)`，`InOrder(root)` 和 `PostOrder(root)`。 下面是修改后的代码： ``` #include <stdio.h> #include <stdlib.h> typedef int DataType; typedef struct Node { DataType data; struct Node *LChild; struct Node *RChild; } BiTNode, *BiTree; //创建二叉树 void createTree(BiTree *root) { int data; scanf("%d", &data); if (data == -1) { //输入-1表示结束 *root = NULL; } else { *root = (BiTree)malloc(sizeof(BiTNode)); (*root)->data = data; createTree(&((*root)->LChild)); createTree(&((*root)->RChild)); } } //先序遍历 void PreOrder(BiTree root) { if (root != NULL) { printf("%d ", root->data); //访问根 PreOrder(root->LChild); //访问左子树 PreOrder(root->RChild); //访问右子树 } } //中序遍历 void InOrder(BiTree root) { if (root != NULL) { InOrder(root->LChild); printf("%d ", root->data); InOrder(root->RChild); } } //后序遍历 void PostOrder(BiTree root) { if (root != NULL) { PostOrder(root->LChild); PostOrder(root->RChild); printf("%d ", root->data); } } int main() { int i; BiTree root = NULL; createTree(&root); printf("请输入你的选择：\n"); scanf("%d", &i); switch (i) { case 1: printf("PreOrder:\n"); PreOrder(root); break; case 2: printf("InOrder:\n"); InOrder(root); break; case 3: printf("PostOrder:\n"); PostOrder(root); break; } printf("\n"); return 0; } ```

### 完整的C语言代码示例：递归实现二叉树操作并整合Huffman编码功能 以下是一个完整的C语言代码示例，包含二叉树的创建、中序/前序/后序遍历、计算深度、统计节点数、叶节点数、度为1的节点数、叶子到根路径以及Huffman编码功能。 ```c #include <stdio.h> #include <stdlib.h> #include <limits.h> #include <string.h> typedef char DataType; // 定义二叉树节点结构 typedef struct Node { DataType data; struct Node* LChild; struct Node* RChild; } BiTNode, *BiTree; // 创建二叉树 void CreateBiTree(BiTree* bt) { char ch; scanf(" %c", &ch); if (ch == '.') { *bt = NULL; } else { *bt = (BiTree)malloc(sizeof(BiTNode)); (*bt)->data = ch; CreateBiTree(&((*bt)->LChild)); CreateBiTree(&((*bt)->RChild)); } } // 前序遍历 void PreOrder(BiTree root) { if (root != NULL) { printf("%c ", root->data); PreOrder(root->LChild); PreOrder(root->RChild); } } // 中序遍历 void InOrder(BiTree root) { if (root != NULL) { InOrder(root->LChild); printf("%c ", root->data); InOrder(root->RChild); } } // 后序遍历 void PostOrder(BiTree root) { if (root != NULL) { PostOrder(root->LChild); PostOrder(root->RChild); printf("%c ", root->data); } } // 计算二叉树的深度 int Depth(BiTree root) { if (root == NULL) return 0; int leftDepth = Depth(root->LChild); int rightDepth = Depth(root->RChild); return (leftDepth > rightDepth ? leftDepth : rightDepth) + 1; } // 统计结点个数 int CountNodes(BiTree root) { if (root == NULL) return 0; return CountNodes(root->LChild) + CountNodes(root->RChild) + 1; } // 统计叶结点个数 int CountLeaves(BiTree root) { if (root == NULL) return 0; if (root->LChild == NULL && root->RChild == NULL) return 1; return CountLeaves(root->LChild) + CountLeaves(root->RChild); } // 统计度为1的结点个数 int CountDegreeOne(BiTree root) { if (root == NULL) return 0; if ((root->LChild != NULL && root->RChild == NULL) || (root->LChild == NULL && root->RChild != NULL)) { return CountDegreeOne(root->LChild) + CountDegreeOne(root->RChild) + 1; } return CountDegreeOne(root->LChild) + CountDegreeOne(root->RChild); } // 输出从叶子到根的路径 void PrintPath(char path[], int len) { for (int i = len - 1; i >= 0; i--) { printf("%c ", path[i]); } printf("\n"); } void FindPath(BiTree root, char path[], int len) { if (root == NULL) return; path[len] = root->data; if (root->LChild == NULL && root->RChild == NULL) { PrintPath(path, len + 1); } else { FindPath(root->LChild, path, len + 1); FindPath(root->RChild, path, len + 1); } } // Huffman编码相关定义 typedef struct HuffmanTreeNode { int weight; char data; struct HuffmanTreeNode* left; struct HuffmanTreeNode* right; } HuffmanTreeNode; // 创建Huffman树 HuffmanTreeNode* CreateHuffmanTree(int weights[], char datas[], int n) { HuffmanTreeNode* nodes[n]; for (int i = 0; i < n; i++) { nodes[i] = (HuffmanTreeNode*)malloc(sizeof(HuffmanTreeNode)); nodes[i]->weight = weights[i]; nodes[i]->data = datas[i]; nodes[i]->left = nodes[i]->right = NULL; } for (int i = 0; i < n - 1; i++) { int firstMin = -1, secondMin = -1; int min1 = INT32_MAX, min2 = INT32_MAX; for (int j = 0; j < n + i; j++) { if (nodes[j]->weight < min1 && nodes[j] != NULL) { min2 = min1; secondMin = firstMin; min1 = nodes[j]->weight; firstMin = j; } else if (nodes[j]->weight < min2 && nodes[j] != NULL) { min2 = nodes[j]->weight; secondMin = j; } } HuffmanTreeNode* parent = (HuffmanTreeNode*)malloc(sizeof(HuffmanTreeNode)); parent->weight = min1 + min2; parent->data = '\0'; parent->left = nodes[firstMin]; parent->right = nodes[secondMin]; nodes[firstMin] = NULL; nodes[secondMin] = NULL; nodes[n + i] = parent; } return nodes[n + n - 2]; } // 生成Huffman编码 void GenerateCodes(HuffmanTreeNode* root, char code[], int top, char codes[][100]) { if (root->left == NULL && root->right == NULL) { codes[root->data] = (char*)malloc((top + 1) * sizeof(char)); for (int i = 0; i < top; i++) { codes[root->data][i] = code[i]; } codes[root->data][top] = '\0'; return; } code[top] = '0'; GenerateCodes(root->left, code, top + 1, codes); code[top] = '1'; GenerateCodes(root->right, code, top + 1, codes); } int main() { BiTree tree; printf("请输入二叉树的先序序列（用.表示空节点）：\n"); CreateBiTree(&tree); printf("前序遍历："); PreOrder(tree); printf("\n"); printf("中序遍历："); InOrder(tree); printf("\n"); printf("后序遍历："); PostOrder(tree); printf("\n"); printf("二叉树的深度：%d\n", Depth(tree)); printf("结点总数：%d\n", CountNodes(tree)); printf("叶结点总数：%d\n", CountLeaves(tree)); printf("度为1的结点总数：%d\n", CountDegreeOne(tree)); char path[100]; printf("从叶子到根的路径：\n"); FindPath(tree, path, 0); // Huffman编码测试 int weights[] = {5, 9, 12, 13, 16, 45}; char datas[] = {'A', 'B', 'C', 'D', 'E', 'F'}; int n = sizeof(weights) / sizeof(weights[0]); HuffmanTreeNode* huffmanTree = CreateHuffmanTree(weights, datas, n); char code[100]; char codes[100][100]; GenerateCodes(huffmanTree, code, 0, codes); printf("Huffman编码：\n"); for (int i = 0; i < n; i++) { printf("%c: %s\n", datas[i], codes[datas[i]]); } return 0; } ``` ###