Middle& Middle::add_year(int n) {
if(n == 0) return *this;
int sign = -1;
if( n > 0) {
sign = 1;
}
if(isLeapYear()) {
if(std::abs(n) > 3 && isLeapYear(year() + 4*sign)) {
_numeric += (365*4 + 1 )*sign;
n -= sign * 4;
return add_year(n);
}else if((sign > 0 && (month() < 3 && !(month() == 2 && day() == 29 ))) ||
(sign < 0 && (month() > 2 || (month() == 2 && day() == 29 )))) {
_numeric += 366 * sign;
n -= sign;
return add_year(n);
}
} else if(isLeapYear(year() + sign) &&
((( month() > 2 || (month() == 2 && day() == 29 ))&& sign > 0) ||
(sign < 0 && (month() < 3 && !(month() == 2 && day() == 29 ))))) {
_numeric += 366 * sign;
n -= sign;
return add_year(n);
}
_numeric += 365 * sign;
n -= sign;
return add_year(n);
}
/*
* add @n months to date
*/
Date& Date::add_month(int n)
{
if (n) {
int mm;
int yy;
yy = n / 12;
mm = m + n % 12;
// left n add m great than 12
if (mm > 12) {
yy++;
mm -= 12;
}
// month first
m = Month(mm);
if (d > month_days(m, y))
d = month_days(m, y);
add_year(yy);
cache->valid = false;
}
return *this;
}
lab2::Gregorian::Gregorian(int y, int m, int d) {
unsigned const yc = y;
unsigned const mc = m;
unsigned const dc = d;
if((y == 0 && m <= 2) || y < 0 || y > 3000 || m > 12 || m < 1 || d < 1 || (int)days_in_month(mc, yc) < d || (d == 29 && m == 2 && is_leap_year(y) == 0)) {
throw std::invalid_argument("Not a valid date");
}
ejd = fjd;
while(y >= 400) {
y -= 400;
ejd += 97 * 366 + 303 * 365;
}
while(y >= 100) {
y -= 100;
ejd += 24 * 366 + 76 * 365;
}
while(y >= 4) {
y -= 4;
ejd += 366 + 3 * 365;
}
while(y >= 1) {
y --;
ejd += 365;
}
while(m > 1) {
ejd += month_lengths[m-2];
m--;
}
//Correct off-by-a-little problems.
add_year(yc-year());
add_month(mc-month());
ejd+=(dc-day());
}
TEST(question1_test6, years_test)
{
actual_date.year=2012;
actual_date.month=12;
actual_date.day=31;
add_year(actual_date); //add year
expected_date.year=2013;
expected_date.month=12;
expected_date.day=31;
CHECK_DATES(expected_date,actual_date);
}
void Date::add_month(int n) {
int yearShift = (int) floor( (double) (((int) _month) + n -1)/ ((int) month_this_year()));
//if(n < 0){yearShift--;}
add_year(yearShift);
_month = ((12+(((int)_month-1+ n ) % 12)) % 12) +1;
//Updating year according to removed/added number of month
if(_day>days_this_month()){
_day = days_this_month();
}
}
void Date:: add_day(int n)
{
// once every 4 years we have a leap year (366 days), vs the normal 365 days.
const int leap_cycle = 365*4+1; // If a user gives us a large number (multiple years), we can speed up the process by adding 4 years at a time.
int year_incr = ( n/leap_cycle) *4; // how many ears to increment (4 years in a leap cycle
n %= leap_cycle; // the remaining number is guaranteed to be less then 4 years.
// add support for negative n:
if (n<0) {
year_incr -= 4; // subtract extra 4 years
n += leap_cycle; // now n is positive. And we can use the old code.
}
add_year( year_incr); // add this big chunk (or zero)
int cur_month_length = days_in_month(m,y); // will give the number of days in a given month
if (cur_month_length - d >= n) // do we stay within a given month?
{
// we do stay within the current month, we just change the date
d += n;
return;
} else {
// first go to the beginning of the next month:
++m; // next month
if (m==Month::jan) // check if we wrapped into a new year
y++;
n -= (cur_month_length - d + 1); // this is what we used up from the previous month
// note that if we start on the last of the month, d = cur_month_lenght, and we are using one day when we skip 31 Jan -> 1 Feb
d=1; // beginning of the month
cur_month_length = days_in_month(m,y); // will give the number of days in a given month
while (cur_month_length - d < n){ // we can increment the full month. 1 Jan -> 1 Feb -> 1 Mar->...
n -= cur_month_length;
// go to the next month: 1 Jan -> 1 Feb -> 1 Mar->...
++m; // next month
if (m==Month::jan) // check if we wrapped into a new year
y++;
cur_month_length = days_in_month(m,y); // prepare for the next iteration
}
// once we are here, the remaining n should be small enough to keep us within a given month.
// d =1
d+= n;
}
}
void Date::add_month(int n)
// If you add a month to 31 Jan you will get 28 or 29 Feb (depending on the leap year)
{
int year = n/12;
int num_month = n % 12; // this should be between 0 and 11
if (num_month<0) { // support the negative n as well.
year -=1; // year was already negative
num_month += 12; // and now we adjusted num_month (num_month is positive) and the old code should work
}
int original_day = d; // need to save it, otherwise add_year can modify for 29 Feb
add_year(year); // this should add the whole number of years (or subtract). Possible side-effect - modifies 29Feb.
d = original_day; // This step was only required for Feb 29.
for (int i=0; i<num_month; i++) {
++m; // increment the month.
if (m== Month::jan)
++y; // we wrapped into the next year.
}
int days_in_month = 31; // most months have 31 days
switch (m) {
case Month::feb: // the length of February varies
days_in_month = (leapyear(y))?29:28;
break;
case Month::apr: case Month::jun: case Month::sep: case Month::nov:
days_in_month = 30; // the rest have 30 days
break;
}
if (days_in_month<d)
d = days_in_month; // set the last of the month
}
