以下是我收到的文件，我被告知不要改变这两个文件中的任何一个。函数的规范在头文件中，main.c是一个测试代码的shell：
#ifndef _DateH_
#define _DateH_
typedef struct {
int month;
int day;
int year;
} date;
int is_leap_year(int the_year);
int days_in_month(int month,int leap_year);
// Recommendation: use switch statement
void input_date(date *dp); // User input of form mm/dd/yyyy
// where mm, dd and yyy are integers
// NO PROMPT JUST INPUT
void print_date(date d); // Output format same as input_date's input format
int day_of_year(date d); // Number of days since beginning of year
// January 1 is day 1 (not 0)
int compare_dates(date d1, date d2);
// Returns -1 if d1 earlier than d2, 0 if same date, +1 if d1 after d2
void check_age_and_birthday(date birthdate, date today);
// Output: "You are __ years old and this is your birthday\n"
// or "You are __ years old and this is not your birthday\n"
void submit_status(date start, date end, date submit);
// Prints ""Submission not accepted - too early\n" if submit < start;
// "Submission not accepted too - late\n" if end < submit;
// "Submission accepted\n" otherwise.
#endif
// Note: A year is a leap year if and only if it is divisible by 4
// and, if it is divisible by 100, it is also divisible by 400.
#include "date.h"
#include <stdio.h>
int main()
{
date d,bdate,today,start,end,submit;
printf("Enter a date: ");
input_date(&d);
printf("\n");
print_date(d);
printf(" is day %d of year %d, which is ",day_of_year(d),d.year);
if (!is_leap_year(d.year))
printf("not ");
printf("a leap year\n\n");
printf("Enter your birthdate: ");
input_date(&bdate);
printf("Enter today's date: ");
input_date(&today);
printf("\n");
check_age_and_birthday(bdate,today);
printf("\nEnter the start date: ");
input_date(&start);
printf("Enter the end date: ");
input_date(&end);
printf("Enter the date submitted: ");
input_date(&submit);
printf("\n\n");
submit_status(start,end,submit);
return 0;
}
#include "date.h"
int is_leap_year(int the_year)
{
if (the_year % 4 == 0) {
if (the_year % 100 == 0) {
if (the_year % 400 == 0) {
return (1);
}
else return (0);
}
else return (1);
}
else return (0);
}
int days_in_month(int month, int leap_year)
{
switch (month) {
case 1: {
return (31);
break;
}
case 2: {
if (leap_year) return (29);
else return (28);
break;
}
case 3: {
return (31);
break;
}
case 4: {
return (30);
break;
}
case 5: {
return (31);
break;
}
case 6: {
return (30);
break;
}
case 7: {
return (31);
break;
}
case 8: {
return (31);
break;
}
case 9: {
return (30);
break;
}
case 10: {
return (31);
break;
}
case 11: {
return (30);
break;
}
case 12: {
return (31);
break;
}
}
}
void input_date(date *dp)
{
do
{
scanf("%d/%d/%d", dp->month, dp->day, dp->year);
}
while
(dp->day > days_in_month(dp->month, is_leap_year(dp->year)) || dp->day < 1);
}
void print_date(date d)
{
printf("%d/%d/%d", d.month, d.day, d.year);
}
int day_of_year(date d)
{
int day_sum = 0;
int i;
if (is_leap_year(d.year))
{
for (i = 1; i < d.month; i++)
{
day_sum = day_sum + days_in_month(i, 1);
}
}
else
{
for (i = 1; i < d.month; i++)
{
day_sum += days_in_month(i, 0);
}
}
day_sum += d.day;
return (day_sum);
}
void check_age_and_birthday(date birthdate, date today)
{
int age;
if (today.month > birthdate.month)
{
age = today.year - birthdate.year;
}
if (today.month < birthdate.month)
{
age = (today.year - birthdate.year) - 1;
}
if (today.month == birthdate.month)
{
if ((today.day > birthdate.day) || (today.day == birthdate.day)) {
age = today.year - birthdate.year;
}
if (today.day < birthdate.day) {
age = (today.year - birthdate.year) - 1;
}
}
if (!compare_dates(birthdate, today))
{
printf ("You are %d years old and this is your birthday\n", age);
}
else
{
printf ("You are %d years old and this is not your birthday\n", age);
}
}
int compare_dates(date d1, date d2)
{
if (d1.year > d2.year)
{
return (1);
}
if (d1.year < d2.year)
{
return (-1);
}
if (d1.year == d2.year)
{
if (d1.month > d2.month)
{
return (1);
}
if (d1.month < d2.month)
{
return (-1);
}
if (d1.month == d2.month)
{
if (d1.day > d2.day)
{
return (1);
}
if (d1.day < d2.day)
{
return (-1);
}
if (d1.day == d2.day)
{
return (0);
}
}
}
}
void submit_status(date start, date end, date submit)
{
if (compare_dates(submit, start) == -1)
{
printf("Submission not accepted - too early\n");
}
if (compare_dates(submit, end) == 1)
{
printf("Submission not accepted - too late\n");
}
if ((compare_dates(submit, start) == 1) && (compare_dates(submit, end) == -1))
{
printf("Submission accepted\n");
}
}
当我将它们放入“控制台应用程序”项目并构建它时，我收到错误：
[Linker error] undefined reference to `submit_status'
ld returned 1 exit status
[Build Error] [DateStruct.exe] Error 1
如果我在单独的标签中运行它们，没有创建任何项目，我会得到：
mangled line number section.
[Linker error] undefined reference to `WinMain@16'
ld returned 1 exit status
我正在使用Dev-C ++。
答案 0 :(得分：0)
当您输入日期时，您的程序会崩溃，因为您将dp->month，dp->day和dp->year的值传递给scanf()。 scanf()需要一个指针来存储结果;在C中，整数看起来像一个指针，所以它很乐意尝试将dp->month中的单位化值解释为指针，然后崩溃，因为它无法在那里写入。
您想要使用&dp->month等。
我建议编译启用所有警告（我不知道Dev-C ++，但GCC标志是-Wall -Wextra）;我还建议使用-Werror处理错误警告，以免意外忽略它们。如果我在启用警告的情况下编译，GCC会告诉我这个问题：
cc -Wall -Werror -Wextra struct.c -o struct
struct.c: In function ‘main’:
struct.c:13:3: error: format ‘%d’ expects argument of type ‘int *’, but argument 2 has type ‘int’ [-Werror=format]
struct.c:13:3: error: format ‘%d’ expects argument of type ‘int *’, but argument 3 has type ‘int’ [-Werror=format]
cc1: all warnings being treated as errors
此示例错误也来自我编写的一个非常快速的测试文件。如果您尝试创建short, self-contained example问题，那么在调试问题时会非常有帮助，如果您遇到问题则会提出问题。你发布的代码有很多无关的内容;几个头文件，你实际上从未实现的功能，等等。将代码剥离成问题的最小示例可以帮助您自己找到问题，或者失败，给出一个更容易让其他人浏览并查看问题的示例，而无需涉及一堆额外的东西
以下是演示此问题的最小示例：
#include <stdio.h>
struct foo {
int bar;
int baz;
};
int main() {
struct foo x, *px;
px = &x;
printf("Enter bar and baz: \n");
scanf("%d %d", px->bar, px->baz);
printf("Got: %d %d\n", px->bar, px->baz);
return 0;
}
以及如何解决它：
#include <stdio.h>
struct foo {
int bar;
int baz;
};
int main() {
struct foo x, *px;
px = &x;
printf("Enter bar and baz: \n");
scanf("%d %d", &px->bar, &px->baz);
printf("Got: %d %d\n", px->bar, px->baz);
return 0;
}