#include <stdio.h>
#include <conio.h>
const int month_table[] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
const int leap_month_table[] = {31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};
//check leap year or not
#define IS_LEAP_YEAR(year) (((year%400 == 0) || (year%4 == 0 && year%100 != 0))? true : false)
bool validDate(int, int, int);
int getTotalDayinMonth(int, int);
void findPreDate(int*, int*, int*);
void findNextDate(int*, int*, int*);
int main()
{
int day, month, year;
int tempDay, tempMonth, tempYear;
int sel;
int totalDay;
printf("******Calendar*********\n");
do
{
printf("day = "); scanf("%d", &day);
printf("\nmonth = "); scanf("%d", &month);
printf("\nyear = "); scanf("%d", &year);
}while(!validDate(day, month, year));
printf("\n****chon 1 trong cac so****\n\
1.so ngay trong thang\n\
2. ngay trc do\n\
3. ngay tiep theo\n\
Other. Exit");
do
{
printf("\n\nlua chon so: ");
scanf("%d", &sel);
switch(sel)
{
case 1:
totalDay = getTotalDayinMonth(month, year);
printf("\nSo Thhang %d is: %d", month, totalDay);
break;
case 2:
tempDay = day; tempMonth = month; tempYear = year;
findPreDate(&tempDay, &tempMonth, &tempYear);
if(validDate(tempDay, tempMonth, tempYear))
{
printf("\nThe previous date is %02d/%02d/%04d", tempDay, tempMonth, tempYear);
}
else
{
printf("\nThe date is invalid");
}
break;
case 3:
tempDay = day; tempMonth = month; tempYear = year;
findNextDate(&tempDay, &tempMonth, &tempYear);
if(validDate(tempDay, tempMonth, tempYear))
{
printf("\nNgay tiep theo %02d/%02d/%04d", tempDay, tempMonth, tempYear);
}
else
{
printf("\nNgay khong hop le");
}
break;
default:
printf("\nExit");
}
}while(sel == 1 || sel == 2 || sel == 3);
getch();
return 0;
}
int getTotalDayinMonth(int month, int year)
{
return (IS_LEAP_YEAR(year) ? leap_month_table[month-1] : month_table[month-1]);
}
bool validDate(int day, int month, int year)
{
// validate dd/mm/yyyy
if (year < 1 || year > 9999 ||
month < 1 || month > 12 ||
day < 1 || day > 31)
{
return false;
}
if(day > getTotalDayinMonth(month, year))
{
return false;
}
return true;
}
void findPreDate(int *day, int* month, int* year)
{
(*day)--;
if (*day < 1)
{
(*month)--;
if (*month < 1) { (*year)--; if(*year == 0) { *month = 0; *day = 0; return; } else *month = 12; } *day = getTotalDayinMonth(*month, *year); } } void findNextDate(int *day, int* month, int* year) { (*day)++; if(*day > getTotalDayinMonth(*month, *year))
{
*day = 1;
(*month)++;
if (*month > 12)
{
*month = 1;
(*year)++;
}
}
}
