数据结构与算法分析习题4.33和4.34

// 辅助函数，计算x坐标
static SearchTree set_x_func(SearchTree tree, int *last_node_x) {
    if (tree == NULL) {
        return NULL;
    }

    tree->left = set_x_func(tree->left, last_node_x);
    tree->x = ++(*last_node_x);
    tree->right = set_x_func(tree->right, last_node_x);

    return tree;
}

// 计算节点的x坐标
SearchTree set_x_position(SearchTree tree) {
    int last_node_x = 0;

    return set_x_func(tree, &last_node_x);
}

// 辅助函数，计算y坐标
static SearchTree set_y_func(SearchTree tree, int depth) {
    if (tree == NULL) {
        return NULL;
    }

    set_y_func(tree->left, depth + 1);
    tree->y = -depth;
    set_y_func(tree->right, depth + 1);

    return tree;
}

// 计算节点的y坐标
SearchTree set_y_position(SearchTree tree) {
    return set_y_func(tree, 0);  // 从深度0开始
}

// 生成画圆指令
static void generate_instructions(SearchTree tree, int *current_index) {
    if (tree == NULL) {
        return;
    }

    // 生成圆的指令
    printf("Circle(%d, %d)第%d个圆\n", tree->x, tree->y, *current_index);
    int this_index = (*current_index)++; // 当前节点索引

    // 初始化左右子树的索引
    int left_index = *current_index; // 左子树的起始索引

    // 递归生成左子树
    generate_instructions(tree->left, current_index);
    if (tree->left) {
        printf("DrawLine(%d, %d)\n", this_index, left_index);
    }

    // 记录右子树的索引
    int right_index = *current_index; // 右子树的起始索引

    // 递归生成右子树
    generate_instructions(tree->right, current_index);
    if (tree->right) {
        printf("DrawLine(%d, %d)\n", this_index, right_index);
    }
}

void generate_tree_instructions(SearchTree tree) {
    int current_index = 1; // 从1开始
    generate_instructions(tree, ¤t_index);
}