c_kitap

C ve Sistem Programcıları Derneği - C Ders Notları - Necati Ergin
if (d < 1 || d > daytabs[isleap(y)][m])
return false;
return true;
}
/*************************************************************************/
PRIVATE int totaldays(const Date *ptr)
{
int sum = 0;
int k;
for (k = YEAR_BASE; k < ptr->m_y; ++k)
sum += 365 + isleap(k);
return sum + get_yearday(ptr);
}
/*************************************************************************/
PRIVATE Date revdate(int totaldays)
{
Date ret_val;
int val;
int index;
ret_val.m_y = YEAR_BASE;
while (totaldays > (val = isleap(ret_val.m_y) + 365)) {
totaldays -= val;
ret_val.m_y++;
}
ret_val.m_m = 1;
index = isleap(ret_val.m_y);
while (totaldays > daytabs[index][ret_val.m_m])
totaldays -= daytabs[index][ret_val.m_m++];
ret_val.m_d = totaldays;
return ret_val;
}
/*************************************************************************/
PUBLIC int get_yearday(const Date *ptr)
{
int sum = ptr->m_d;
int k;
int index = isleap(ptr->m_y);
for (k = 1; k < ptr->m_m; ++k)
sum += daytabs[index][k];
return sum;
}
/*************************************************************************/
PUBLIC int dayofweek(const Date *ptr)
{
return totaldays(ptr) % 7;
}
/*************************************************************************/
PUBLIC bool isleap(int y)
{
return y % 4 == 0 && y % 100 != 0 || y % 400 == 0;
}
/*************************************************************************/
PUBLIC void set_date(Date *ptr, int d, int m, int y)
{
assert(check_date(d, m, y));
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