有两种方法.

如果在通过值传递指向头节点的指针时使用您的方法，则该函数可以采用以下方式.

If to use your approach when the pointer to the head node is passed by value then the function can look the following way.

node * delete_even_node( node *head )
{
    while ( head && head->data % 2 == 0 )
    {
        node *tmp = head;
        head = head->next;
        free( tmp );
    }

    if ( head )
    {
        node *current = head;
        while ( current->next )
        {
            if ( current->next->data % 2 == 0 )
            {
                node *tmp = current->next;
                current->next = current->next->next;
                free( tmp );
            }
            else
            {
                current = current->next;
            }
        }
    }

    return head;
}

另一种方法是通过引用将指针传递到头节点.

Another approach is to pass the pointer to the head node by reference.

例如

void delete_even_node( node **head )
{
    while ( *head )
    {
        if ( ( *head )->data % 2 == 0 )
        {
            node *tmp = *head;
            *head = ( *head )->next;
            free( tmp );
        }
        else
        {
            head = &( *head )->next;
        }
    }
}

该函数的调用方式类似于

And the function is called like

delete_even_node( &head );