Here's my java solution if(year>=1919 && year<=2700){ if(year%4==0 && (year%100!=0 || year%400==0)){ return 12+".09"+"."+year; }else{ return 13+".09"+"."+year; } }else if(year>=1700 && year<=1917){ if(year%4==0){ return 12+".09"+"."+year; }else{ return 13+".09"+"."+year; } }else{ return "26.09.1918"; }

JavaScript

function dayOfProgrammer(year) {
    return ((year >= 1700 && year < 1918 && year % 4 == 0)
        || (year > 1918 && year <= 2700 && (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)))
        ? "12" : (year == "1918") ? "26" : "13") + ".09." + year;
}

Here is my c++ solution, you can watch the explanation here : https://youtu.be/U1u7Zz4ngVg

string dayOfProgrammer(int year) {
    if(year == 1918) return "26.09.1918";
    if( (year <= 1917 && year % 4 == 0) or (year > 1918) && (year%400 == 0 or ((year%4 == 0) & (year%100 != 0)))) return "12.09."+to_string(year);
    return "13.09." + to_string(year);
}

java(8)

public static String dayOfProgrammer(int year) {
    // Write your code here

    int[] leapYear = { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
    int[] notLeapYear = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

    int month = 0;
    int sumOfDay = 0;

    if (year < 1919) {

        if (year % 4 == 0) {

            while (sumOfDay <= 256) {

                sumOfDay += leapYear[month];
                month++;

            }
            if (sumOfDay > 256) {
                sumOfDay -= leapYear[month - 1];
            }
        } else if (year % 4 != 0) {

            while (sumOfDay <= 256) {

                sumOfDay += notLeapYear[month];
                month++;
            }
            if (sumOfDay > 256) {
                sumOfDay -= notLeapYear[month - 1];
            }

        }

    }

    else if (year > 1918) {
        if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) {
            while (sumOfDay <= 256) {

                sumOfDay += leapYear[month];
                month++;
            }
            if (sumOfDay > 256) {
                sumOfDay -= leapYear[month - 1];
            }

        } else {

            while (sumOfDay <= 256) {

                sumOfDay += notLeapYear[month];
                month++;
            }
            if (sumOfDay > 256) {
                sumOfDay -= notLeapYear[month - 1];
            }

        }
    }

    int date = 256 - sumOfDay;

    String m;
    if (month < 12) {
        String fL = "0";
        m = fL + Integer.toString(month);
    } else {
        m = Integer.toString(month);
    }
    String d = Integer.toString(date);
    String y = Integer.toString(year);

    return d + "." + m + "." + y;

}

can anybody explain to me how 2017 is a leap year but 2016 is not???