树的广义表表示法C语言代码

以下是树的广义表表示法的C语言代码：

#include <stdio.h>
#include <stdlib.h>

typedef struct node {
    char data;
    struct node *firstchild, *nextsibling;
} Node;

Node *createNode(char data) {
    Node *newNode = (Node*)malloc(sizeof(Node));
    newNode->data = data;
    newNode->firstchild = NULL;
    newNode->nextsibling = NULL;
    return newNode;
}

Node *createTree(char* str, int* index) {
    Node *root = NULL;
    Node *currentNode = NULL;
    int i = *index;
    while (str[i] != '\0') {
        if (str[i] == '(') {
            i++;
            if (root == NULL) {
                root = createNode(str[i]);
                currentNode = root;
            } else {
                Node *newNode = createNode(str[i]);
                if (currentNode->firstchild == NULL) {
                    currentNode->firstchild = newNode;
                } else {
                    Node *temp = currentNode->firstchild;
                    while (temp->nextsibling != NULL) {
                        temp = temp->nextsibling;
                    }
                    temp->nextsibling = newNode;
                }
                currentNode = newNode;
            }
        } else if (str[i] == ')') {
            currentNode = currentNode->nextsibling;
        } else if (str[i] == ',') {
            i++;
            Node *newNode = createNode(str[i]);
            Node *temp = currentNode->nextsibling;
            while (temp->nextsibling != NULL) {
                temp = temp->nextsibling;
            }
            temp->nextsibling = newNode;
            currentNode = newNode;
        }
        i++;
    }
    return root;
}

void printTree(Node *root) {
    if (root != NULL) {
        printf("%c", root->data);
        if (root->firstchild != NULL) {
            printf("(");
            printTree(root->firstchild);
            printf(")");
        }
        if (root->nextsibling != NULL) {
            printf(",");
            printTree(root->nextsibling);
        }
    }
}

int main() {
    char* str = "A(B(C,D),E(F(G(H))))";
    int index = 0;
    Node *root = createTree(str, &index);
    printTree(root);
    printf("\n");
    return 0;
}

该代码实现了树的广义表表示法的创建和打印功能，其中createNode函数用于创建节点，createTree函数用于创建树，printTree函数用于打印树。在该示例代码中，字符串"A(B(C,D),E(F(G(H))))"表示的是下图所示的树：

  A
 / \
B   E
|   |
C   F
 \   \
  D   G
      |
      H