Question

完全是C的新手，我试图在C中创建一个按字母顺序对预先存在的char数组进行排序的链表。每个字符都分配了一个索引。所以listInsert函数应该将每个字符串插入到链表中并按字母顺序排序，这样当调用listPrintForward时，链表中的项目将按字母顺序打印。

这是我运行程序时的当前输出。

http://imgur.com/cZxx0rr

INSERT:
bravo oscar romeo delta whisky alpha
foxtro sierra yankee lima echo
golf november victor charlie mike
zulu tango kilo quebec hotel
juliet xray papa uniform india

FORWARD: 0 entries
india uniform papa xray juliet hotel
quebec kilo tango zulu mike
charlie victor november golf echo
lima yankee sierra foxtrot alpha
whisky delta romeo oscar bravo

正如你可以看到我的listInsert函数当前所做的就是将它们插入一个链表（我认为），并且当调用printForward函数时，它会反转链表的内容，当它应该打印链接的内容时按字母顺序列出。

我想要的输出应该是：

INSERT:
bravo oscar romeo delta whisky alpha
foxtro sierra yankee lima echo
golf november victor charlie mike
zulu tango kilo quebec hotel
juliet xray papa uniform india

FORWARD: 0 entries
alpha bravo charlie delta echo foxtrot
golf hotel india juliet kilo
lima mike november oscar papa
quebec romeo sierra tango uniform
victor whisky xray yankee zulu

有谁知道如何解决这个或我做错了什么？这是完整的代码：

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

#define SUCCESS 0
#define FAIL    1

char *phonetic[] = { "alpha", "bravo", "charlie", "delta", "echo", "foxtrot",
                     "golf", "hotel", "india", "juliet", "kilo", "lima", "mike",
                     "november", "oscar", "papa", "quebec", "romeo", "sierra",
                     "tango", "uniform", "victor", "whisky", "xray", "yankee", 
                     "zulu" };

unsigned char indexes[] = { 1, 14, 17, 3, 22, 0, 5, 18, 24, 11, 4, 6, 13, 21,
                            2, 12, 25, 19, 10, 16, 7, 9, 23, 15, 20, 8 };                       

// represents an entry in the linked-list
struct listEntry
{
  char *data_p;               // pointer to the entry's string
  struct listEntry *prev_p;   // pointer to previous entry in the linked-list  
  struct listEntry *next_p;   // pointer to next entry in the linked-list
};

// represents the linked-list
struct list
{
  int entryCount;             // number of entries present in the linked-list
  struct listEntry *head_p;   // pointer to the first entry in the list  
  struct listEntry *tail_p;   // pointer to the last entry in the list
};

// Dynamically allocate & initialise an empty linked list
int listCreate(struct list** list_p2)
{
  // allocate struct list from heap 
  *list_p2 = (struct list*) malloc(sizeof(**list_p2));

  if (*list_p2 != NULL)
  {
    // zero-initialize the list structure 
    memset(*list_p2, 0, sizeof(**list_p2));
    return SUCCESS;    
  }

  return FAIL;
}

// Free all entries in the linked-list and the list structure
int listDestroy(struct list *list_p)
{
  if (list_p != NULL)
  {
    struct listEntry *entry_p = list_p->head_p;

    while (entry_p != NULL)
    {
      struct listEntry *next_p = entry_p->next_p;
      // free the current entry
      free(entry_p);
      // move to the next entry
      entry_p = next_p;
    }

    // free list structure
    free(list_p);
  }

  return FAIL;
}

// Traverse the linked-list from head to tail printing out
// the string data from each list entry
int listPrintForward(struct list *list_p)
{ 
  if (list_p)
  {    
    struct listEntry *entry_p = list_p->head_p;
    int count = 0;

    printf("FORWARD: %d entries\n", list_p->entryCount);
    while (entry_p != NULL)
    {
      if ((count > 0) && (count % 5 == 0))
      {
        printf("%s\n", entry_p->data_p);
      }
      else
      {      
        printf("%s ", entry_p->data_p);
      }

      if (entry_p == list_p->tail_p)
        printf("\n");

      entry_p = entry_p->next_p;
      fflush(stdout);
      count++;         
    }

    return SUCCESS;
  }

  return FAIL;
}

// Traverse the linked-list from tail to head printing out
// the string data from each list entry
int listPrintReverse(struct list *list_p)
{ 
  if (list_p)
  {    
    struct listEntry *entry_p = list_p->tail_p;
    int count = 0;

    printf("REVERSE: %d entries\n", list_p->entryCount);   
    while (entry_p != NULL)
    {
      if ((count > 0) && (count % 5 == 0))
      {
        printf("%s\n", entry_p->data_p);
      }
      else
      {      
        printf("%s ", entry_p->data_p);
      }

      if (entry_p == list_p->head_p)
        printf("\n");

      entry_p = entry_p->prev_p;
      fflush(stdout);
      count++;         
    }

    return SUCCESS;
  }

  return FAIL;
}

// Insert the given string into the linked-list such that the
// entries in the linked-list are in alphabetical order
int listInsert(struct list *list_p, char *string_p)
{ 
    struct listEntry *temp;
    temp=(struct listEntry *)malloc(sizeof(struct listEntry)); 
    temp->data_p = string_p;

    if (list_p->head_p == NULL)
    {
        //List is Empty
        list_p->head_p = temp;
        temp->next_p = NULL;
    }
    else
    {
        temp->next_p =list_p->head_p;
        list_p->head_p = temp;
    }


  return FAIL;  
}

int main(int argc, char **argv)
{
  struct list *list_p = NULL;
  (void) argc;
  (void) argv;

  if (listCreate(&list_p) == SUCCESS)
  {
    unsigned int count;

    // insert every word in the phonetic alphabet into the
    // linked-list.
    printf("INSERT:\n");
    for (count = 0; count < sizeof(indexes); count++)
    {
      if ((count > 0) && (count % 5 == 0))
      {
        printf("%s\n", phonetic[indexes[count]]);
      }
      else
      {
        printf("%s ", phonetic[indexes[count]]);
      }
      listInsert(list_p, phonetic[indexes[count]]);
    }
    printf("\n");

    // print out the list in alphabetical order
    listPrintForward(list_p);
    // print out the list in reverse alphabetical order
    listPrintReverse(list_p); 

    // Destroy the linked list and free all associated memory
    listDestroy(list_p);               
  }

  return SUCCESS;
}

Answer 1

您按索引顺序插入条目。你应该对temp-＆gt; p_data进行strcmp，然后从头到尾遍历列表并插入节点。

请参阅http://analgorithmaday.blogspot.nl/2011/01/insertion-sort-using-linked-list.html

提示

问候

约翰

排序链接列表在C中无法正常工作

1 个答案: