为什么我的 C 队列中出现分段错误(核心已转储)?
Why am i gettting segmentation fault (core dumped) in my C queue?
所以我试图在 C 中实现队列数据结构,但我不断收到此错误:分段错误(核心已转储)。我认为它来自我的排队方法。谁能帮我解决这个问题...
这是我的 queue.c 文件
#include <stdio.h>
#include <stdlib.h>
#include "queue.h"
void createQueue(LinkedList* list)
{
list = (LinkedList*)calloc(1, sizeof(LinkedList));
}
int isEmpty(LinkedList* list)
{
int empty = 0;
if(list->head == NULL)
{
empty = 1;
}
return empty;
}
void enqueue(LinkedList* list, Person p)
{
LinkedListNode* newNode = (LinkedListNode*)malloc(sizeof(LinkedListNode));
newNode->data = p;
if (isEmpty(list))
{
list->head = list->tail = newNode;
} else
{
LinkedListNode* first = list->head;
first->previous = newNode;
newNode->next = list->head;
list->head = newNode;
}
list->count ++;
}
Person dequeue(LinkedList* list)
{
LinkedListNode* temp;
temp = list->tail;
list->tail = list->tail->previous;
list->count --;
return temp->data;
}
void viewQueue(LinkedList* list)
{
LinkedListNode* current;
current = list->head;
while (current != NULL)
{
printf("Name: %s Birthdate: %s\n", current->data.name, current->data.birthdate);
current = current->next;
}
printf("\nPeople: %d\n", list->count);
}
这是我的头文件...
#ifndef LINKED_LIST
#define LINKED_LIST
#define FALSE 0
#define TRUE !FALSE
typedef struct{
char name[20];
char birthdate[10];
} Person;
typedef struct LinkedListNode{
Person data;
struct LinkedListNode* next;
struct LinkedListNode* previous;
} LinkedListNode;
typedef struct{
LinkedListNode* head;
LinkedListNode* tail;
int count;
} LinkedList;
void createQueue(LinkedList* list);
int isEmpty(LinkedList* list);
void enqueue(LinkedList* list, Person p);
Person dequeue(LinkedList* list);
void viewQueue(LinkedList* list);
#endif
我也有这个方法来测试我的队列。当我 运行 它出现分段错误时。我的程序有什么问题?
#include <stdio.h>
#include "queue.h"
int main(void)
{
LinkedList* list;
createQueue(list);
Person p1 = {"J Cole", "28/01/1985"};
Person p2 = {"Kendrick Lamar", "19/01/1994"};
Person p3 = {"Slim Shady", "17/10/1972"};
Person p4 = {"Tupac Shakur", "12/09/1971"};
enqueue(list, p1);
enqueue(list, p2);
enqueue(list, p3);
enqueue(list, p4);
viewQueue(list);
return 0;
}
您正在传递列表指针的值。您需要传递引用。
void createQueue(LinkedList** list)
{
*list = (LinkedList*)calloc(1, sizeof(LinkedList));
}
从主要
createQueue(&list);
将值(如指针)传递给例程时,为了让例程设置该值,您必须传递其地址。因此,这一行:
createQueue(list);
应该是:
createQueue(&list);
如果您希望 createQueue 设置 变量的值。您还需要:
void createQueue(LinkedList** list)
{
*list = (LinkedList*) calloc(1, sizeof(LinkedList));
}
别担心——每个 C 程序员都曾在某个时候犯过这个错误。有关详细信息,请搜索 "Pass by value or reference" 和 "c pointer to pointer."
所以我试图在 C 中实现队列数据结构,但我不断收到此错误:分段错误(核心已转储)。我认为它来自我的排队方法。谁能帮我解决这个问题...
这是我的 queue.c 文件
#include <stdio.h>
#include <stdlib.h>
#include "queue.h"
void createQueue(LinkedList* list)
{
list = (LinkedList*)calloc(1, sizeof(LinkedList));
}
int isEmpty(LinkedList* list)
{
int empty = 0;
if(list->head == NULL)
{
empty = 1;
}
return empty;
}
void enqueue(LinkedList* list, Person p)
{
LinkedListNode* newNode = (LinkedListNode*)malloc(sizeof(LinkedListNode));
newNode->data = p;
if (isEmpty(list))
{
list->head = list->tail = newNode;
} else
{
LinkedListNode* first = list->head;
first->previous = newNode;
newNode->next = list->head;
list->head = newNode;
}
list->count ++;
}
Person dequeue(LinkedList* list)
{
LinkedListNode* temp;
temp = list->tail;
list->tail = list->tail->previous;
list->count --;
return temp->data;
}
void viewQueue(LinkedList* list)
{
LinkedListNode* current;
current = list->head;
while (current != NULL)
{
printf("Name: %s Birthdate: %s\n", current->data.name, current->data.birthdate);
current = current->next;
}
printf("\nPeople: %d\n", list->count);
}
这是我的头文件...
#ifndef LINKED_LIST
#define LINKED_LIST
#define FALSE 0
#define TRUE !FALSE
typedef struct{
char name[20];
char birthdate[10];
} Person;
typedef struct LinkedListNode{
Person data;
struct LinkedListNode* next;
struct LinkedListNode* previous;
} LinkedListNode;
typedef struct{
LinkedListNode* head;
LinkedListNode* tail;
int count;
} LinkedList;
void createQueue(LinkedList* list);
int isEmpty(LinkedList* list);
void enqueue(LinkedList* list, Person p);
Person dequeue(LinkedList* list);
void viewQueue(LinkedList* list);
#endif
我也有这个方法来测试我的队列。当我 运行 它出现分段错误时。我的程序有什么问题?
#include <stdio.h>
#include "queue.h"
int main(void)
{
LinkedList* list;
createQueue(list);
Person p1 = {"J Cole", "28/01/1985"};
Person p2 = {"Kendrick Lamar", "19/01/1994"};
Person p3 = {"Slim Shady", "17/10/1972"};
Person p4 = {"Tupac Shakur", "12/09/1971"};
enqueue(list, p1);
enqueue(list, p2);
enqueue(list, p3);
enqueue(list, p4);
viewQueue(list);
return 0;
}
您正在传递列表指针的值。您需要传递引用。
void createQueue(LinkedList** list)
{
*list = (LinkedList*)calloc(1, sizeof(LinkedList));
}
从主要
createQueue(&list);
将值(如指针)传递给例程时,为了让例程设置该值,您必须传递其地址。因此,这一行:
createQueue(list);
应该是:
createQueue(&list);
如果您希望 createQueue 设置 变量的值。您还需要:
void createQueue(LinkedList** list)
{
*list = (LinkedList*) calloc(1, sizeof(LinkedList));
}
别担心——每个 C 程序员都曾在某个时候犯过这个错误。有关详细信息,请搜索 "Pass by value or reference" 和 "c pointer to pointer."