指向传递给函数的结构体的指针

发布于 2024-12-11 16:37:44 字数 608 浏览 0 评论 0原文

这是我的程序的精简版本。我需要将指向结构指针的指针传递给函数，修改函数内的结构，并使这些更改持续存在。函数声明必须保持不变。

目前我可以修改函数内的数据，但是一旦返回到main，就没有进行任何更改。

感谢您的帮助。

int main()
{
    struct node** HuffmanNodes;
    read_Huffman_encoded_data(&HuffmanNodes);
}

void read_Huffman_encoded_data(**HuffmanNodes)
{
    Huffman_node = (node**)malloc(sizeof(node*)*(*number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_node[index] = (node*)malloc(sizeof(node));
        Huffman_node[index]->first_value=1;
        Huffman_node[index]->second_value=2;
    }
}

原文

This is a stripped down version of my program. I need to pass a pointer to pointers of structs to a function, modify the structs within the function, and have those changes persist. The function declaration must stay the same.

Currently I can modify the data within the function, but once returned to main, no changes were made.

Thank you for your help.

int main()
{
    struct node** HuffmanNodes;
    read_Huffman_encoded_data(&HuffmanNodes);
}

void read_Huffman_encoded_data(**HuffmanNodes)
{
    Huffman_node = (node**)malloc(sizeof(node*)*(*number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_node[index] = (node*)malloc(sizeof(node));
        Huffman_node[index]->first_value=1;
        Huffman_node[index]->second_value=2;
    }
}

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和影子一齐双人舞 2024-12-18 16:37:44

你有一个指针输入问题。我很惊讶它甚至可以编译，因为 &HuffmanNodes 是 node*** 类型。

试试这个：

void read_Huffman_encoded_data(struct node ***HuffmanNodes)
{
    *Huffman_nodes = (node**)malloc(sizeof(node*)*(*number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        (*Huffman_nodes)[index] = (node*)malloc(sizeof(node));
        (*Huffman_nodes)[index]->first_value=1;
        (*Huffman_nodes)[index]->second_value=2;
    }
}

你还有一些命名不匹配（我已修复），我希望这些只是剥离程序时的拼写错误。

编辑：替代方法

int main()
{
    struct node** HuffmanNodes = (node*)malloc(sizeof(node) * (*number_of_nodes));
    read_Huffman_encoded_data(HHuffmanNodes);
}

void read_Huffman_encoded_data(struct node **HuffmanNodes)
{
    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_nodes[index] = (node*)malloc(sizeof(node));
        Huffman_nodes[index]->first_value=1;
        Huffman_nodes[index]->second_value=2;
    }
}

You have a pointer typing problem. I'm surprised that it even compiles since &HuffmanNodes is of type node***.

Try this:

void read_Huffman_encoded_data(struct node ***HuffmanNodes)
{
    *Huffman_nodes = (node**)malloc(sizeof(node*)*(*number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        (*Huffman_nodes)[index] = (node*)malloc(sizeof(node));
        (*Huffman_nodes)[index]->first_value=1;
        (*Huffman_nodes)[index]->second_value=2;
    }
}

You also have some naming mismatches (which I fixed), I hope those are just typos from stripping down the program.

EDIT: Alternative Method

int main()
{
    struct node** HuffmanNodes = (node*)malloc(sizeof(node) * (*number_of_nodes));
    read_Huffman_encoded_data(HHuffmanNodes);
}

void read_Huffman_encoded_data(struct node **HuffmanNodes)
{
    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_nodes[index] = (node*)malloc(sizeof(node));
        Huffman_nodes[index]->first_value=1;
        Huffman_nodes[index]->second_value=2;
    }
}

回复收藏 0 原文

小伙你站住 2024-12-18 16:37:44

试试这个：

int main()
{
    struct node** HuffmanNodes;
    read_Huffman_encoded_data(&HuffmanNodes);
}

void read_Huffman_encoded_data(**HuffmanNodes)
{
    Huffman_node = (node*)malloc(sizeof(node)*(number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_node[index] = (node*)malloc(sizeof(node));
        Huffman_node[index]->first_value=1;
        Huffman_node[index]->second_value=2;
    }
}

Try this:

int main()
{
    struct node** HuffmanNodes;
    read_Huffman_encoded_data(&HuffmanNodes);
}

void read_Huffman_encoded_data(**HuffmanNodes)
{
    Huffman_node = (node*)malloc(sizeof(node)*(number_of_nodes));

    int index;
    for(index=0; index<*number_of_nodes;index++)
    {
        Huffman_node[index] = (node*)malloc(sizeof(node));
        Huffman_node[index]->first_value=1;
        Huffman_node[index]->second_value=2;
    }
}

回复收藏 0 原文

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