[HaBo]

if((jahr%4 == 0 && jahr%100 != 0) || jahr%400 == 0)

#include <iostream>
using namespace std;

short datum_pruefen(short, short, int);
short tage_berechnen(short, short, int);

int main()
{

short tag,monat, pruefen;
int jahr, tage;

cout << "Bitte ein Datum eingeben (Syntax: TT MM YYYY, ohne Punkt!)." << endl;
cout << "Datum: ";
cin >> tag >> monat >> jahr;
cin.get();


pruefen = datum_pruefen(tag, monat, jahr);

if(pruefen == 0)
{
cout << "Falsches Datum!n";

return 0;
}

cout << "nDatum korrekt!" << endl;

tage = tage_berechnen(tag, monat, jahr);

cout << "nZeitraum vom 1.1." << jahr << " bis zum "
<< tag << "." << monat << "." << jahr << endl
<< "Tag(e): " << tage << endl;

cout << "nEnter zum beenden druecken.";


cin.get();
return 0;
}

short datum_pruefen(short tag, short monat, int jahr)
{
switch (monat)
{
case 1:
if(tag <= 31)
return 1;

return 0;
break;

case 2:
if((jahr%4 == 0 && jahr%100 != 0) || jahr%400 == 0)
{
if(tag <= 29)
return 1;
}
if(tag <= 28)
return 1;

return 0;
break;

case 3:
if(tag <= 31)
return 1;

return 0;
break;

case 4:
if(tag <= 30)
return 1;

return 0;
break;

case 5:
if(tag <= 31)
return 1;

return 0;
break;

case 6:
if(tag <= 30)
return 1;

return 0;
break;

case 7:
case 8:
if(tag <= 31)
return 1;

return 0;
break;
case 9:
if(tag <= 30)
return 1;

return 0;
break;

case 10:
if(tag <= 31)
return 1;

return 0;
break;

case 11:
if(tag <= 30)
return 1;

return 0;
break;

case 12:
if(tag <= 31)
return 1;

return 0;
break;

default:
return 0;
break;
}

return 1;
}

short tage_berechnen(short tag, short monat, int jahr)
{
short tage = 0;

short monate[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };

monat--;
for(int i=0;i<monat;i++)
tage += monate[i];
monat++;

tage += tag;

if((jahr%4 == 0 && jahr%100 != 0) || jahr%400 == 0)
tage++;

return tage;
}

#include <stdio.h>

int mon[12] =
{ /* Jan */ 0,
  /* Feb */ 31,
  /* Mar */ 31+28,
  /* Apr */ 31+28+31,
  /* Mai */ 31+28+31+30,
  /* Jun */ 31+28+31+30+31,
  /* Jul */ 31+28+31+30+31+30,
  /* Aug */ 31+28+31+30+31+30+31,
  /* Sep */ 31+28+31+30+31+30+31+31,
  /* Okt */ 31+28+31+30+31+30+31+31+30,
  /* Nov */ 31+28+31+30+31+30+31+31+30+31,
  /* Dez */ 31+28+31+30+31+30+31+31+30+31+30
};

unsigned long Get_Tage(int tag, int monat, int jahr)
{
  unsigned long tage;

  tage = jahr*365+((jahr-1)/4)-((jahr-1)/100)+((jahr-1)/400);
  tage += mon[monat-1];
  if (monat > 2)
    { if ((jahr%  4)==0) tage++;
      if ((jahr%100)==0) tage--;
      if ((jahr%400)==0) tage++;
    }
  tage += tag-1;

  return(tage);
}

int main()
{
  int geboren, heute;

  geboren = Get_Tage(18, 9, 1972);
  heute = Get_Tage(8, 9, 2005);
  printf("tage = %i\n", heute-geboren);
  return(-1);
}

//Tagerechner.java

import java.io.*;

class Datum {
  int tag = 1;
  int monat = 1;
  int jahr = 1901;
  boolean schaltjahr = false;
  int month[] = new int[12];
  
  void getDatum() throws IOException
  {
    month[0]=31;	month[1]=28;	month[2]=31;
    month[3]=30;	month[4]=31;	month[5]=30;
    month[6]=31;	month[7]=31;	month[8]=30;
    month[9]=31;	month[10]=30;	month[11]=31;
    
    BufferedReader din = new BufferedReader(new InputStreamReader(System.in));
    do {
      System.out.println("Tag: ");
      tag = Integer.parseInt(din.readLine());
    } while (tag <= 0 || tag > 31);
    
    do {
      System.out.println("Monat (1-12): ");
      monat = Integer.parseInt(din.readLine());
      monat--;
    } while (monat < 0 || monat > 12);
    
    while (tag > month[monat] || tag <= 0) {
      System.out.println("Der eingegebene Tag ist ungültig.\nTag: ");
      tag = Integer.parseInt(din.readLine());
    }
    
    do {
      System.out.println("Jahr: ");
      jahr = Integer.parseInt(din.readLine());
    } while (jahr < 0);
  }
  
  void ifSchaltjahr()
  {
    if (jahr%400 == 0) {
      month[1] = 29;
    } else if (jahr%4 == 0 && jahr%100 != 0) {
      month[1] = 29;
    } else {
      month[1] = 28;
    }
  }
    
  void printTage()
  {
    int tage = 0;
    // Tage der Monate werden nach und nach hinzugezählt
    
    for (int i=0; i<monat; i++)
    {
      tage += month[i];
    }
    // Tage im aktiven Monat werden hinzugezählt
    tage += tag;
    // Ergebnis wird ausgegeben
    System.out.println("Zeitspanne vom 1.1." + jahr + 
                       " bis zum " + tag + "." + (monat+1) + "." + jahr + ": "
                       + tage + " Tage");
  }
}


public class Tagerechner
{
  public static void main(String[] args) throws IOException
  {
    Datum date = new Datum();
    date.getDatum();
    date.ifSchaltjahr();
    date.printTage();
  }
}

import java.io.*;
import java.util.StringTokenizer;

public class PrintDays {

	// the day count of the months ( be careful with february )
	static int months[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	
	// main function
	public static void main(String[] args) {
		StringTokenizer datum = new StringTokenizer(readDatum());
		int day = Integer.valueOf(datum.nextToken(".")).intValue();
		int month = Integer.valueOf(datum.nextToken(".")).intValue();
		int year = Integer.valueOf(datum.nextToken(".")).intValue();
		
		if(datum.hasMoreElements()){
			System.out.println("Fehler bei der Eingabe, bitte nutzen Sie das angegebene Format.");
			System.exit(-1);
		}
		
		System.out.println("\nEs sind " + calculateDays(day,month,year) 
				+ " Tage seit dem 01.01." + year + " vergangen");
	}
	
	// reads the date
	public static String readDatum(){
		String input = null;
		
		System.out.println("Bitte geben Sie ein Datum ein. Format DD.MM.YYYY");
		System.out.print("> ");
		try{
			BufferedReader in = new BufferedReader( new InputStreamReader(System.in) );
			input = in.readLine();
		} catch(Exception e){
			System.out.println("Fehler bei der Eingabe");
			System.exit(-1);
		}
		return input;
	}
	
	// calculate days
	public static int calculateDays(int day, int month, int year){

		int days = 0;
		
		if( (year%4==0 && year%100!=0) || year%400==0 ){
			months[1] = 29;
		}
		
		// check if month is correct
		if(month <= 0 || month > 12){
			System.out.println("Sie haben ein ungueltiges Datum angegeben.");
			System.exit(-1);
		}
		
		// check if day is correct
		if(day > months[month-1] || day <= 0){
			System.out.println("Sie haben ein ungueltiges Datum angegeben.");
			System.exit(-1);
		}
		
		// adding days of month
		for(int i = 0; i < month-1; i++){
			days += months[i];
		}
		
		// adding days of current month
		days += day;		
		
		return days;
	}
}

#include <cstdio>
#include <cstdlib>
#include <iostream.h>

//prototype of getdays
int getdays(int days,int month,int year);

//main function
int main()
{
    cout << "Welcome to count days v0.0001 by Ancient 4 Hackerboard.de progamming challenge\n"
         << "Please enter a date in the format dd mm yyyy\n";
    int d,m,y;
    cin >> d >> m >> y;
    cout << "Thank you\n";
    if (getdays(d,m,y) > 0)
    {
    cout << "Days passed from 01.01." << y << " until " << d << "." << m << "." << y << ": " << getdays(d,m,y);
    }
    else 
    {
     cout << "Told ya an error occured";
     return 0;
    }
    return 0;
}

//real getdays function
int getdays(int days,int month,int year)
{
    //int array of months with corresponding day values
    int monarray[] = {0,31,28,31,30,31,30,31,31,30,31,30,31};
    //answer variable
    int totaldays = 0;
    //check that user entries are valid
    if ((month < 13 && month > 0) && (days <= monarray[month]))
    {
     //add number of days of all full months passed at user date
     for(int i = 1 ; i < month ; i++) 
     {
            totaldays = totaldays + monarray[i];
            
     }
     //if leapyear and february included then total days incremented by 1 
     if ((year%400 == 0 || year%4 == 0) && (month > 2))
     {
               totaldays += 1;
     }
              totaldays = totaldays + days;
              return totaldays;
    }
    else 
    {
         cout << "an error has occured we will now terminate try again with real values goodbye\n" ;
         return 0;
   }
}

#include <iostream>

int main(void)
{
int d,m,y,days = 0;
short months[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

std::cout << "Datum eingeben(dd mm yyyy):\n";
std::cin  >> d >> m >> y;

for (int i = 0;  i < m-1  ;i++)
 days += months[i];

if(((y % 4) == 0 || (y % 400) == 0) && (m > 2) )
 ++days;

std::cout << "Seit dem 1.1. sind " << (days + d) << " Tage vergangen!\n";

return 0;
}

#include <iostream>

int main(void)
{
int d,m,y,days = 0;
short months[12] = {31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

std::cout << "Datum eingeben(dd mm yyyy):\n";
std::cin  >> d >> m >> y;

if(d > months[d] || m > 12 )
 return -1;

for (int i = 0;  i < m-1  ;i++)
 days += months[i];

if(((y % 4) == 0 || (y % 400) == 0) && (m > 2) )
 ++days;

std::cout << "Seit dem 1.1. sind " << (days + d) << " Tage vergangen!\n";

return 0;
}

if((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)