利用链接栈实现二叉树的前序遍历的全代码C++

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

#define MAXSIZE 100

typedef struct TreeNode {
    char value;
    struct TreeNode *left;
    struct TreeNode *right;
} TreeNode;

typedef struct Stack {
    TreeNode *data[MAXSIZE];
    int top;
} Stack;

void initStack(Stack *s) {
    s->top = -1;
}

void push(Stack *s, TreeNode *node) {
    if (s->top == MAXSIZE - 1) {
        printf("Stack overflow\n");
        return;
    }
    s->top++;
    s->data[s->top] = node;
}

TreeNode *pop(Stack *s) {
    if (s->top == -1) {
        printf("Stack underflow\n");
        return NULL;
    }
    TreeNode *node = s->data[s->top];
    s->top--;
    return node;
}

TreeNode *createTreeNode(char value) {
    TreeNode *node = (TreeNode *)malloc(sizeof(TreeNode));
    node->value = value;
    node->left = NULL;
    node->right = NULL;
    return node;
}

TreeNode *createBinaryTree(char *s, int *index) {
    if (s[*index] == '\0') {
        return NULL;
    }
    if (s[*index] == '#') {
        (*index)++;
        return NULL;
    }
    TreeNode *node = createTreeNode(s[*index]);
    (*index)++;
    node->left = createBinaryTree(s, index);
    (*index)++;
    node->right = createBinaryTree(s, index);
    return node;
}

void preOrderTraversalWithStack(TreeNode *root) {
    if (root == NULL) {
        return;
    }
    Stack s;
    initStack(&s);
    push(&s, root);
    while (s.top != -1) {
        TreeNode *node = pop(&s);
        printf("%c ", node->value);
        if (node->right != NULL) {
            push(&s, node->right);
        }
        if (node->left != NULL) {
            push(&s, node->left);
        }
    }
}

int main() {
    char s[] = "AB#D##C##";
    int index = 0;
    TreeNode *root = createBinaryTree(s, &index);
    printf("Pre-order traversal with stack: ");
    preOrderTraversalWithStack(root);
    printf("\n");
    return 0;
}