我剛剛開始學習C,我對它仍然很陌生。 在這個程序中,我正在處理一系列結構。的結構是:結構中使用qsort()
typedef struct {
int day;
int month;
int year;
} Date;
typedef struct {
int serial_num;
char full_name[15];
Date *pDate;
} Person;
陣列是Person *people
。
現在我的那些人的人,出生日期兩個數組(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 }
};
通過使用switch case
,每次用戶類型1從列表中的人(姓名和生日)是添加到列表people
。然後,如果用戶鍵入3,則列表people
應該按日期排序(從最舊到最新)。所以我寫了下面的兩個功能:
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;
}
但每次我得到一個錯誤的時間說:
Exception thrown: read access violation.
one->pDate was nullptr.
任何幫助嗎? 謝謝!
編輯: 進一步說明:爲了將人員逐一插入數組,我創建了一個名爲index的變量,每次添加一個人時索引都會增加一個。所以當調用函數qsort()時,index
是數組中的人數。也MAX=7, COLS=3, LEN=10
。這增加了人們對陣列的功能是:
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;
}
請提供[MCVE。例如'index'的價值是什麼,'people'是什麼? – Stargateur
向我們展示了填充數組'people'的代碼 –
對不起,添加了變量和填充'people'的函數。 – eitanmayer