import?java.util.regex.Matcher;
import?java.util.regex.Pattern;
public?class?第幾天?{
public?static?void?main(String[]?args)?{
try?{
System.out.println(相差天數("2016-7-30",?"2015-7-30"));
}?catch?(Exception?e)?{
e.printStackTrace();
}
}
private?static?Pattern?p?=?Pattern.compile("(\\d{4})-(\\d{1,2})-(\\d{1,2})");
public?static?int?相差天數(String?a,?String?b)?throws?Exception?{
Matcher?m?=?p.matcher(a);
if?(!m.matches())
throw?new?Exception();
int?y1?=?Integer.parseInt(m.group(1));
int?m1?=?Integer.parseInt(m.group(2));
int?d1?=?Integer.parseInt(m.group(3));
m?=?p.matcher(b);
if?(!m.matches())
throw?new?Exception();
int?y2?=?Integer.parseInt(m.group(1));
int?m2?=?Integer.parseInt(m.group(2));
int?d2?=?Integer.parseInt(m.group(3));
return?相差天數(y1,?m1,?d1,?y2,?m2,?d2);
}
public?static?int?相差天數(int?y1,?int?m1,?int?d1,?int?y2,?int?m2,?int?d2)?{
return?總第幾天(y1,?m1,?d1)?-?總第幾天(y2,?m2,?d2);
}
public?static?int?總第幾天(int?y,?int?m,?int?d)?{
int?a?=?(y?-?1)?*?365?+?(y?-?1)?/?4?-?(y?-?1)?/?100?+?(y?-?1)?/?400;
return?a?+?年第幾天(y,?m,?d);
}
public?static?int?年第幾天(int?y,?int?m,?int?d)?{
return?閏年(y)潤年月前天數[m]?+?d?:?平年月前天數[m]?+?d;
}
public?static?boolean?閏年(int?年)?{
return?年?%?400?==?0?||?(年?%?4?==?0?&&?年?%?100?!=?0);
}
private?static?final?int[]?平年月天數?=?{?0,?31,?28,?31,?30,?31,?30,?31,?31,?30,?31,?30,?31?};
private?static?final?int[]?平年月前天數?=?new?int[14],?潤年月前天數?=?new?int[14];
static?{
int?n?=?0;
for?(int?i?=?1;?i?<=?12;?i++)?{
平年月前天數[i]?=?n;
潤年月前天數[i]?=?i?>?2n?+?1?:?n;
n?+=?平年月天數[i];
}
平年月前天數[13]?=?n;
潤年月前天數[13]?=?n?+?1;
}
}