http://kor.i2p/books/The%20C%20Programming%20Language%20by%20K&R/chapter5.html?i2paddresshelper=XeeEcrjZBSZvLCLt32HWWojBguqcQNIfCcYnLhCSpV3LHMHvq-3nkdVw3DGoJYEQnLEpbhLEH~KwUXs42auWcbRedx895ciACwHpMBnchqCYvYeqKNOnMnlZkpSGJNNSRXAcUM48WLh7v6PscDCDKQFN8KVo9n6OBm0KKQjmaQjIN3unappXVvN90d0Q6tWjftn1mTtm2Is4sYYM3glXr47IXPjTha~XW6Ex5wNqtD7pR5rNN5g5Xcpww2teT~mo52Z1xFE5g7ZgK3rHRVnShmolLNwU2VT1ZGqI5X74Tq6DPu6itln3SYyF6db-X
= 0 || year%400 == 0;
for (i = 1; i < month; i++)
day += daytab[leap][i];
return day;
}
/* month_day: set month, day from day of year */
void month_day(int year, int yearday, int *pmonth, int *pday)
{
int i, leap;
leap = year%4 == 0 && year%100 !