我刚刚开始学习C,我对它仍然很陌生。 在这个程序中,我正在处理一系列结构。的结构是:结构中使用qsort()
typedef struct {
int day;
int month;
int year;
} Date;
typedef struct {
int serial_num;
char full_name[15];
Date *pDate;
} Person;
阵列是Person *people
。
现在我的那些人的人,出生日期两个数组(同一索引):
const char* names[MAX] = { "Sasson_Sassoni", "Pooh", "James_Bond", "Elvis_is_Alive", "Shilgiya", "Cleopatra", "Sissoo_VeSimmhoo" };
const int dates[MAX][COLS] = {
{ 10, 1, 1988 },
{ 12, 12, 1948 },
{ 4, 12, 1970 },
{ 11, 11, 1890 },
{ 11, 11, 1948 },
{ 1, 10, 1213 },
{ 12, 11, 1948 }
};
通过使用switch case
,每次用户类型1从列表中的人(姓名和生日)是添加到列表people
。然后,如果用户键入3,则列表people
应该按日期排序(从最旧到最新)。所以我写了下面的两个功能:
void sortList(Person **people, int index) {
qsort(*people, index, sizeof(Person), intcmp);
}
int intcmp(const void *a, const void *b) {
Person *one = (Person *)a;
Person *two = (Person *)b;
int year1 = one->pDate->year;
int year2 = two->pDate->year;
int month1 = one->pDate->month;
int month2 = two->pDate->month;
int day1 = one->pDate->day;
int day2 = two->pDate->day;
if (year1 > year2)
return -1;
else if (year2 > year1)
return 1;
if (month1 > month2)
return -1;
else if (month2 > month1)
return 1;
if (day1 > day2)
return -1;
else if (day2 > day1)
return 1;
return 0;
}
但每次我得到一个错误的时间说:
Exception thrown: read access violation.
one->pDate was nullptr.
任何帮助吗? 谢谢!
编辑: 进一步说明:为了将人员逐一插入数组,我创建了一个名为index的变量,每次添加一个人时索引都会增加一个。所以当调用函数qsort()时,index
是数组中的人数。也MAX=7, COLS=3, LEN=10
。这增加了人们对阵列的功能是:
void addToList(Person **people, int *index, const char *names[MAX], const int dates[][COLS]) {
people[*index] = (Person *)malloc(sizeof(Person));
people[*index]->serial_num = *index + 1;
strcpy(people[*index]->full_name, names[*index]);
Date *temp = (Date *)malloc(sizeof(Date));
temp->day = dates[*index][0];
temp->month = dates[*index][1];
temp->year = dates[*index][2];
people[*index]->pDate = temp;
printf("%d %s %d/%d/%d \n", people[*index]->serial_num, people[*index]->full_name, people[*index]->pDate->day, people[*index]->pDate->month, people[*index]->pDate->year);
*index = *index + 1;
}
请提供[MCVE。例如'index'的价值是什么,'people'是什么? – Stargateur
向我们展示了填充数组'people'的代码 –
对不起,添加了变量和填充'people'的函数。 – eitanmayer