Question

我已经成功创建了一个新的，更大的哈希表，它重新散列当前表中的数据并将其插入到新表中。然而，事实证明我想要做出的改变是在本地反映出来的，而不是传递给主要的。在下面的代码段的底部，我注释了**listarray=**listarray2;行，因为我不认为这就是我想要发生的事情。我知道代码的其余部分正常工作，因为在我的insert（）函数中，不同的数组位置存储相同的值。

我唯一的问题：如何让listarray2覆盖listarray，以便它作为我的默认表反映在main中？

void resizeTable (node **listarray, int *size)
{
    //listarray is an array of node*, declared in main just like listarray2
    //size is 8, should reflect the change to 11 back in main

    int newSize= 11;
    node *temp; //iterating pointer

    node **listarray2= malloc (sizeof (node*) * newSize); //create space for a new array of node*'s

    for(i=0;i<newSize;i++)
        listarray2[i]=NULL; //set everything inside to NULL

    //go through original listarray (of size 8)
    for(i=0;i<(*size);i++) 
    {
        if (listarray[i]==NULL) //ignore empty array positions
            continue;

        temp=listarray[i]; //temp now points to a node that is not NULL

        while(temp!=NULL) //until the end of the list in that particular array
        {
            //arg1 is the new list,arg2 is the new Size 11, arg3 is the data from the to-be-old hash table
            insert(&*listarray2,newSize,temp->data);
            temp=temp->next;
        }
    }
    //free(listarray);
    //**listarray=**listarray2;


    *size = newSize;
}//end resize()

Answer 1

为了清楚起见，重命名一些变量，你会这样做：

#include "assert.h"

void resizeTable (node ***p_listarray, int *p_size)
{
    //listarray is an array of node*, declared in main just like newListarray
    //size is 8, should reflect the change to 11 back in main
    node **newListarray;
    int newSize= 11;
    node **oldListarray;
    int oldSize;
    int i;

    assert(p_listarray != NULL);  /* From http://en.wikipedia.org/wiki/Assert.h */
    assert(p_size != NULL); /* From http://en.wikipedia.org/wiki/Assert.h */

    oldListarray = *p_listarray;
    oldSize = *p_size;

    newListarray = malloc (sizeof (node*) * newSize); //create space for a new array of node*'s

    for(i=0;i<newSize;i++)
        newListarray[i]=NULL; //set everything inside to NULL

    //go through original listarray (of size 8)
    for(i=0;i<oldSize;i++) 
    {
        node *temp; //iterating pointer

        if (oldListarray[i]==NULL) //ignore empty array positions
            continue;
        temp=oldListarray[i]; //temp now points to a node that is not NULL
        while(temp!=NULL) //until the end of the list in that particular array
        {
            //arg1 is the new list,arg2 is the new Size 11, arg3 is the data from the to-be-old hash table
            insert(&*newListarray,newSize,temp->data);
            temp=temp->next;
        }
    }

    *p_listarray = newListarray;
    *p_size = newSize;

    free(oldListarray);
}//end resize()

然后将其称为

    node **listarray;
    int size;

    // Initialize the hash table, and then when it needs resizing...
    resizeTable(&listarray, &size);

在C中反映将哈希表重新调整为main

1 个答案: