萬年歷 Beta 1

#include <iostream>
#include <cmath>
using namespace std;
int main()
{
    int date,months,days,years,years_thousand,years_hundred,years_ten,years_one,years_stg_one,years_stg_two;
    cout<<"請輸入年/月/日，用空格分開: ";
    cin>>years>>months>>date;
    if (months == 1) {
        months = 13;
        years = years-1;
    }
    if (months == 2) {
        months=14;
        years = years-1;
    }
    years_thousand=years/1000;
    years_hundred=(years-years_thousand*1000)/100;
    years_ten=(years-years_thousand*1000-years_hundred*100)/10;
    years_one=(years-years_thousand*1000-years_hundred*100-years_ten*10);
    /*
    cout<<"years = "<<years<<endl;
    cout<<"years thousand = "<<years_thousand<<endl;;
    cout<<"Years hundred = "<<years_hundred<<endl;
    cout<<"Years ten = "<<years_ten<<endl;
    cout<<"Years one = "<<years_one<<endl;
    */
    years_stg_one=10*years_thousand+years_hundred;
    years_stg_two=10*years_ten+years_one;
    if (years_stg_one<=15 && years_stg_two<=82 && months<=10 && days<=4) {
        goto befcalc;
    }
    else {
        goto afcalc;
    }
befcalc:
{
    days=(years_stg_two+(years_stg_two/4)-years_stg_one+(26*(months+1)/10)+date+4)%7-1;
    if (days == 0) {
        cout<<"星期天"<<endl;
    }
    else if (days<0) {
        days = days + 7;
        cout<<"星期"<<days<<endl;
    }
    else {
        cout<<"星期"<<days<<endl;
    }
    cout<<(26*(months+1)/10);
    return 0;
}
afcalc:
{
    days=(years_stg_two+(years_stg_two/4)+(years_stg_one/4)-2*years_stg_one+(26*(months+1)/10)+date-1)%7;
    if (days == 0) {
        cout<<"星期天"<<endl;
    }
    else if (days<0) {
        days = (days%7+7)%7;
        cout<<"星期"<<days<<endl;
    }
    else {
        cout<<"星期"<<days<<endl;
    }
    return 0;
    }
    return 0;
}