我正在为我的 CECS 课程分配电话簿，但在按字母顺序排序联系人时遇到了问题。该程序最多允许我对 3 个联系人进行排序，但是当我尝试对 3 个以上的联系人进行排序时，程序开始吐出垃圾变量并可能崩溃。
void Sort(phone *phonebook, int *num_entries)
{
int tracker = *num_entries;
if (tracker >= 0)
{
phone *temp = (phone*) calloc(tracker, sizeof(phone));
if (temp== NULL)
printf("\n\nOut of memory\n\n");
else
{
int i, j;
for (i = 0; i < tracker; i++)
{
for (j = i+1; j < tracker; j++)
{
//Combines first and last names into 1 name for easy comparison
strcpy(phonebook[i].totalname, phonebook[i].fName);
strcpy(phonebook[j].totalname, phonebook[j].fName);
strcat(phonebook[i].totalname, phonebook[i].lName);
strcat(phonebook[j].totalname, phonebook[j].lName);
printf("\nTotal name = %s\nTotal name = %s", phonebook[i].totalname, phonebook[j].totalname); //Done so I can verify it worked correctly
if (strcmp(phonebook[i].totalname, phonebook[j].totalname) > 0)
{
strcpy(temp[i].fName, phonebook[i].fName);
strcpy(temp[i].lName, phonebook[i].lName);
temp[i].number = phonebook[i].number;
temp[i].area = phonebook[i].area;
strcpy(phonebook[i].fName, phonebook[j].fName);
strcpy(phonebook[i].lName, phonebook[j].lName);
phonebook[i].number = phonebook[j].number;
phonebook[i].area = phonebook[j].area;
strcpy(phonebook[j].fName, temp[i].fName);
strcpy(phonebook[j].lName, temp[i].lName);
phonebook[j].number = temp[i].number;
phonebook[j].area = temp[i].area;
}
}
}
printf("\n\nSuccessfully sorted!\n\n");
}
}
else
printf("\n\nYou need people in the phone book before you can sort it.\n\n");
}
-------------------------
typedef struct PhoneBook
{
char fName[20];
char lName[20];
char totalname[40];
float number;
int area;
} phone;
编辑以添加结构。而且我不使用 qsort，因为我们在课堂上还没有学到它，而且 TA 对不使用我们没有学过的东西相当严格。
void Add(phone *phonebook, int *num_entries)
{
int tracker = *num_entries;
if (tracker == 0)
{
printf("\n\nSomething's wrong here\n\n");
}
else
{
const int newSize = tracker + 1;
phone *temp = (phone*) realloc(phonebook, (newSize * sizeof(phone)));
if (temp!=NULL)
{
phonebook = temp;
}
else
phonebook = NULL;
}
if (phonebook == NULL)
printf("\n\nOut of memory, can't add more to your phonebook\n\n");
else
{
printf("\n\nEnter the first name: ");
scanf("%s", phonebook[tracker].fName);
printf("\nPlease enter the last name: ");
scanf("%s", phonebook[tracker].lName);
printf("\nPlease enter the area code: ");
scanf("%d", &phonebook[tracker].area);
printf("\nPlease enter the phone number (no dashes allowed): ");
scanf("%f", &phonebook[tracker].number);
*num_entries += 1;
printf("\nContact Added.\n\n");
}
}
再次编辑以显示将人员添加到电话簿的代码（也已损坏）。在 3-4 个条目之后，它开始为条目放置垃圾值。
int main()
{
int userInput = 8; //means exit
int num_entries = 1;
phone *phonebook = (phone*) calloc(1 , sizeof(phone));
if (phonebook == NULL)
printf("\n\nOut of memory\n\n");
else
{
do
{
system("cls");
printf("Menu: \n");
printf("1) Add a Contact\n");
printf("2) Delete a Contact\n");
printf("3) Display Phone Book\n");
printf("4) Alphabetically Sort\n");
printf("5) Find a Contact\n");
printf("6) Random Contact\n");
printf("7) Delete All\n");
printf("8) Exit\n\n");
scanf(" %d", &userInput);
switch (userInput)
{
case 1: //Add a Friend
Add(phonebook, &num_entries);
break;
case 2: //Delete a Friend
Delete(phonebook, &num_entries);
break;
case 3: //List all contacts
Display(phonebook, &num_entries);
break;
case 4:
Sort(phonebook, &num_entries);
break;
case 5:
Find(phonebook, &num_entries);
break;
case 6:
Random(phonebook, &num_entries);
break;
case 7:
DeleteAll(phonebook, &num_entries);
break;
case 8:
free(phonebook);
break;
}
system("PAUSE");
}while(userInput != 8);
}
return 0;
}
编辑显示每个函数的调用
好吧，我不能在没有更多声誉的情况下发布照片，所以这里是链接：照片 1 - 添加 3 个联系人可以正常工作：http://s980.photobucket.com/user/valondon/media/C%20Realloc%20Errors/Erroronerealloc_zpsc8228131.png。 html?sort=3&o=0 图2 - 添加第四个联系人后的电话簿：http ://s980.photobucket.com/user/valondon/media/C%20Realloc%20Errors/Errorthreerealloc_zps246b76e3.png.html?sort= 3&o=2
