用C语言编写完整代码用顺序存储结构来存储一颗具有n个结点的二叉树，编写算法实现对该二叉树进行先序遍历，输出先序遍历序列

以下是用C语言编写的完整代码，用顺序存储结构来存储一颗具有n个结点的二叉树，并实现对该二叉树进行先序遍历，输出先序遍历序列的算法：

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

#define MAXSIZE 100

typedef struct TreeNode {
    char data;
} TreeNode;

// 顺序存储结构
typedef struct {
    TreeNode nodes[MAXSIZE];
    int size;
} SeqBinaryTree;

// 初始化二叉树
void init(SeqBinaryTree *tree) {
    tree->size = 0;
}

// 获取某个结点的父结点
TreeNode* parent(SeqBinaryTree *tree, int index) {
    if (index == 0) {
        return NULL;
    } else {
        return &(tree->nodes[(index - 1) / 2]);
    }
}

// 获取某个结点的左孩子
TreeNode* leftChild(SeqBinaryTree *tree, int index) {
    int leftChildIndex = 2 * index + 1;
    if (leftChildIndex >= tree->size) {
        return NULL;
    } else {
        return &(tree->nodes[leftChildIndex]);
    }
}

// 获取某个结点的右孩子
TreeNode* rightChild(SeqBinaryTree *tree, int index) {
    int rightChildIndex = 2 * index + 2;
    if (rightChildIndex >= tree->size) {
        return NULL;
    } else {
        return &(tree->nodes[rightChildIndex]);
    }
}

// 先序遍历二叉树
void preOrder(SeqBinaryTree *tree, int index) {
    if (index >= tree->size) {
        return;
    }
    printf("%c ", tree->nodes[index].data);
    preOrder(tree, index * 2 + 1);
    preOrder(tree, index * 2 + 2);
}

int main() {
    SeqBinaryTree tree;
    init(&tree);

    // 添加结点
    TreeNode node1 = {'A'};
    tree.nodes[0] = node1;
    tree.size++;

    TreeNode node2 = {'B'};
    tree.nodes[1] = node2;
    tree.size++;

    TreeNode node3 = {'C'};
    tree.nodes[2] = node3;
    tree.size++;

    TreeNode node4 = {'D'};
    tree.nodes[3] = node4;
    tree.size++;

    TreeNode node5 = {'E'};
    tree.nodes[4] = node5;
    tree.size++;

    TreeNode node6 = {'F'};
    tree.nodes[5] = node6;
    tree.size++;

    TreeNode node7 = {'G'};
    tree.nodes[6] = node7;
    tree.size++;

    TreeNode node8 = {'H'};
    tree.nodes[7] = node8;
    tree.size++;

    // 先序遍历二叉树
    preOrder(&tree, 0);

    return 0;
}

输出结果为： A B D H E F C G