leapYear function
return true if given year is an leap year
Implementation
bool leapYear(int year) {
bool leapYear = false;
bool leap = ((year % 100 == 0) && (year % 400 != 0));
if (leap == true) {
leapYear = false;
} else if (year % 4 == 0) {
leapYear = true;
}
return leapYear;
}