好的，所以我在使用gcc编译时遇到这些错误：
prelab6.h: In function âinsertHeadCircularâ:
prelab6.h:45: error: incompatible types in assignment
prelab6.h:46: error: incompatible types in assignment
prelab6.c: At top level:
prelab6.c:41: warning: data definition has no type or storage class
prelab6.c:41: warning: parameter names (without types) in function declaration
prelab6.c:41: error: conflicting types for âprintInOrderâ
prelab6.h:81: error: previous definition of âprintInOrderâ was here
prelab6.c:42: warning: data definition has no type or storage class
prelab6.c:42: warning: parameter names (without types) in function declaration
prelab6.c:42: error: conflicting types for âprintReverseâ
prelab6.h:112: error: previous definition of âprintReverseâ was here
我已经尝试过，但无法解决这些错误。感谢您的帮助。
这是我的.c文件：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "my.h"
int main ( int argc, char **argv )
{
char firstname[100];
char lastname[100];
int monthsEmployed;
FILE *fptr;
fptr = fopen(argv[1], "r");
if (fptr == NULL)
printf ("Incorrect file reading!");
if (argc != 2)
printf ("Incorrect number of arguments!");
employeeInfo *insert;
insert = malloc(sizeof(employeeInfo));
employeeList *head;
head = NULL;
while(!feof(fptr))
{
fscanf (fptr, "%100s %100s %d", firstname, lastname, &monthsEmployed);
strcpy(insert->firstname, firstname);
strcpy(insert->lastname, lastname);
insert->monthsEmployed = monthsEmployed;
head = insertHeadCircular(head, insert);
}
}
printInOrder(head); // display the linked list
printReverse(head); // display the linked list in reverse
我的.h文件（请注意事情已被注释掉，因为我尝试的方式不同而没有结果）：
typedef struct employeeInfo{
char firstname[100];
char lastname[100];
int monthsEmployed;
}employeeInfo;
//Struct containing pointers to the next and previous used to make a circular linked list
typedef struct list{
employeeInfo emp;
struct list *next;
struct list *previous;
}employeeList;
employeeList *insertHeadCircular(employeeList *head, employeeInfo *emp);
void printInOrder(employeeList head);
void printReverse(employeeList head);
employeeList *insertHeadCircular(employeeList *head, employeeInfo *emp)
{
employeeList *theprevious = head;
employeeList *current;
employeeList *thenext = head;
current = malloc(sizeof(employeeList));
employeeInfo *employee;
if(thenext==NULL)
{
current->next = current;
current->previous = current;
}
else
{
current->next = thenext;
thenext->previous = current;
while(theprevious->next != thenext)
{
theprevious = theprevious->next;
}
current->previous = theprevious;
theprevious->next = current;
}
current->emp = (employeeInfo *)malloc(sizeof(employeeInfo));
employee = current->emp;
employee = malloc(sizeof(employeeInfo));
strcpy(employee->firstname, emp->firstname);
strcpy(employee->lastname, emp->lastname);
employee->monthsEmployed = emp->monthsEmployed;
/*
employeeList *newcell, *first = head;
if(head == NULL)
{
newcell = (struct list *)malloc(sizeof(struct list));
strcpy(newcell->firstname, emp->firstname);
strcpy(newcell->lastname, emp->lastname);
newcell->monthsEmployed = emp->monthsEmployed;
return newcell;
}
while(head->next != first)
{
head = head->next;
}
newcell = (struct list *)malloc(sizeof(struct list));
head->next = newcell;
strcpy(newcell->firstname, emp->firstname);
strcpy(newcell->lastname, emp->lastname);
newcell->monthsEmployed = emp->monthsEmployed;
newcell->next = first;
*/
return current;
}
void printInOrder(employeeList head)
{
/*employeeInfo *first = head;
if (head == NULL)
{
printf("The circularly linked list is empty!\n");
return;
}
do
{
printf("%s %s %d\n", emp.firstname, emp.lastname, head.monthsEmployed);
head = head->next;
} while(head != first);
*/
/*employeeInfo current = head;
employeeInfo start = head;
int loop = 0;
printf("--------------\n");
while(current != start || loop==0)
{
loop++;
printf("Employee: %s %s\nMonths Employed: %d", current->firstname, current->lastname, current->monthsEmployed);
printf("--------------\n");
current=current->next;
}*/
}
void printReverse(employeeList head)
{/*
employeeList current = head
employeeInfo start = head
int theloop=0;
printf("--------------\n");
while(current! = start || loop==0)
{
loop++;
printf("Employee: %s %s\nMonths Employed: %d", current->firstname, current->lastname, current->monthsEmployed);
printf("--------------\n");
current=current->previous;
}*/
}
已编辑的程序
错误：
file.c: In function âmainâ:
file.c:37: error: incompatible type for argument 2 of âinsertHeadCircularâ
.c：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "file.h"
int main ( int argc, char **argv )
{
char firstname[100];
char lastname[100];
int monthsEmployed;
FILE *fptr;
fptr = fopen(argv[1], "r");
if (fptr == NULL)
printf ("Incorrect file reading!");
if (argc != 2)
printf ("Incorrect number of arguments!");
employeeInfo *insert;
insert = malloc(sizeof(employeeInfo));
employeeList *head;
head = NULL;
while(!feof(fptr))
{
fscanf (fptr, "%100s %100s %d", firstname, lastname, &monthsEmployed);
strcpy(insert->firstname, firstname);
strcpy(insert->lastname, lastname);
insert->monthsEmployed = monthsEmployed;
head = insertHeadCircular(head, insert);
}
printInOrder(head); // display the linked list
printReverse(head); // display the linked list in reverse
}
.h：
typedef struct employeeInfo{
char firstname[100];
char lastname[100];
int monthsEmployed;
}employeeInfo;
typedef struct list{
employeeInfo emp;
struct list *next;
struct list *previous;
}employeeList;
typedef employeeList *listnode;
employeeList *insertHeadCircular(employeeList *head, employeeInfo emp);
void printInOrder(employeeList *head);
void printReverse(employeeList *head);
employeeList *insertHeadCircular(employeeList *head, employeeInfo emp)
{
listnode newPtr;
listnode firstPtr;
listnode tempPtr;
newPtr = (employeeList *)malloc(sizeof(employeeList));
strcpy(newPtr->emp.firstname, emp.firstname);
strcpy(newPtr->emp.lastname, emp.lastname);
newPtr->emp.monthsEmployed = emp.monthsEmployed;
if(head == NULL)
{
newPtr->next = newPtr;
newPtr->previous = newPtr;
head = newPtr;
firstPtr = newPtr;
}
else
{
tempPtr = firstPtr;
newPtr->next = tempPtr;
tempPtr->previous = newPtr;
newPtr->previous = head;
head->next = newPtr;
firstPtr = newPtr;
}
return head;
}
void printInOrder(employeeList *head)
{
listnode currentPtr = head;
do
{
printf("%s %s %d\n",currentPtr->emp.firstname, currentPtr->emp.lastname, currentPtr->emp.monthsEmployed);
currentPtr= currentPtr->previous;
}
while(currentPtr !=head);
}
void printReverse(employeeList *head)
{
listnode currentPtr = head->next;
do
{
printf("%s %s %d\n",currentPtr->emp.firstname, currentPtr->emp.lastname, currentPtr->emp.monthsEmployed);
currentPtr = currentPtr->next;
}
while(currentPtr != head->next);
}
答案 0 :(得分：1)
在insertHeadCircular()功能中，您将emp的{{1}}成员视为employeeList。例如，您声明：
employeeInfo *但稍后会这样做：
employeeInfo *employee;
但是，您的employee = current->emp;
类型包含employeeList的实例，而不是指向一个的实例：
employeeInfo所以基本上你需要纠正你的代码，以便停止为指针分配结构，而是将结构的地址<_ em>分配给指针。
您的typedef struct employeeInfo{
char firstname[100];
char lastname[100];
int monthsEmployed;
}employeeInfo;
/* ... */
typedef struct list{
employeeInfo emp; /* see? Not a pointer. */
struct list *next;
struct list *previous;
}employeeList;
和printInOrder()函数最有可能采用printReverse()个参数，而不是employeeList *个参数...并且您应该检查您用于的代码他们确保你不要把两者混淆在一起。
在头文件以外的位置定义函数也是一个好主意，例如在单独的employeeList源文件中。头文件应该只包含其他源文件可能需要的函数原型，宏和其他声明;你不需要那里的函数体，因为链接器可以在从其他源创建的目标文件中找到它们。当头文件由多个文件.c编辑时，在头文件中定义函数会导致无穷无尽的麻烦。
您使用更新的代码#include得到的错误指出您传递给file.c:37: error: incompatible type for argument 2 of âinsertHeadCircularâ的参数类型不是您在声明中提供的类型 - 这是真的。您已声明并定义了该函数，以insertHeadCircular()作为其第二个参数：
employeeInfo ...但是在employeeList *insertHeadCircular(employeeList *head, employeeInfo emp)
中你传给了一个指针：
main()所以你需要改变一个或另一个。从main调用函数时取消引用employeeInfo *insert;
...
head = insertHeadCircular(head, insert);
，或者更改insert以取代指针（并相应地更新主体）。后者可能更好，因为它可以避免在调用函数时将整个结构复制到堆栈中。
要指出的其他一些事情：
您应该在insertHeadCircular()的循环中检查scanf()的回复。它会让你知道是否所有字段都被读取;现在，如果它们不是，你的程序只会继续变量已经存在的任何垃圾（就像上一次迭代中读取的那些，可能）。检查其他返回值（例如从main()返回）也是一个好主意，但在这种情况下，malloc()返回特别重要。
您在节目结束时也不会免费scanf();当你的程序退出时，操作系统（几乎可以肯定）会清理它，但是当你完成它时，最好自己动手。但是，你使用它的方式，你真的不需要动态分配它;你可以刚刚宣布一个insert并取其地址（但无论如何都是这样）。