/* Online Java - IDE, Code Editor, Compiler Online Java is a quick and easy tool that helps you to build, compile, test your programs online. */ public class Main { static int year; // this is the year static String yearString; static String finalDate; //this will be in format DD/MM/YYYY static String finalDatePalindrome; // this will be DDMMYYYY to ensure palindrome check can be complete static Object days; //object since it is extracted from enum value static Object month; //object since it is extracted from enum value static Object objectLeapYearFebruaryDays; //extracted from enum value static int intLeapYearFebruaryDays; //stores 29 on leap year static boolean leapYear; //check if leap year static String temp; static Object prefixZero = "0"; //added to form DD for days less than 10 static int daysMonth; //uses days Object from above static int monthcount; // ensures main do while loop is constrained static String formattedMonth; //obtain correct format such 01, 02... static int ddInt; // used to initiate starting date in for loop... static int mmInt; // used to select month and set month static String ddString; // linked to ddInt static String mmString; //linked to mmInt static boolean processedFirstMonth=false; // used to control ddInt... Once first month is complete, //start date ddInt each month will be 1 //method call to check if palindrome public static void checkPalindrome(String finalDate, String finalDatePalindrome) { //System.out.println("CHECKING!"); String reverseString; int j=0; StringBuffer sb = new StringBuffer(); for (int i=finalDatePalindrome.length()-1; i>=0; i--) { sb.append(finalDatePalindrome.charAt(i)); j++; } reverseString=sb.toString(); if(finalDatePalindrome.equalsIgnoreCase(reverseString)) { System.out.println("Palindrome"); System.out.println(finalDate); // Date will be outputted DD/MM/YYYY } } // enum containing the days, MM enum Months { JAN (31,1), FEB(28,2), MAR(31,3), APR(30,4), MAY(31,5), JUN(30,6), JUL(31,7), AUG(31,8), SEPT(30,9), OCT(31,10), NOV(30,11), DEC(31,12); public int days; public int month; Months (int days, int month) { this.days=days; this.month=month; } } public static void main(String[] args) { System.out.println("Welcome to Online IDE!! Happy Coding :)"); palindromicDates("01/01/2020", 100); } public static void palindromicDates (String date, int years) { int startPos = date.length()-4; // this is marker to start the year YYYY createDate(startPos, date, years); } public static void createDate(int startPos, String date, int years) { yearString = date.substring(startPos, date.length()); year = Integer.valueOf(yearString); ddString = date.substring(0,2); ddInt = Integer.valueOf(ddString); mmString = date.substring(3,5); mmInt = Integer.valueOf(mmString)-1; // this is reduced by 1 since it will be used in contexts // involving zero index notation. boolean newYearRollOver=false; // default value for (int i=0; i<=years; i++) { System.out.println(year); // to ensure memory limit not exceeded, this is only statement printed to Screen //with exception of if palindrome successful newYearRollOver=false; leapYear=false; monthcount=0; do { // processing the months in the enum for (Months m: Months.values()) { switch (mmInt) // this is used to get the correct MM format. // In hindsight, perhaps both parameters in JAN (31,1) should have been string { case 0: formattedMonth = "01"; //System.out.println(m.values()[mmInt].name()); break; case 1: formattedMonth = "02"; //System.out.println(m.values()[mmInt].name()); break; case 2: formattedMonth = "03"; //System.out.println(m.values()[mmInt].name()); break; case 3: formattedMonth = "04"; //System.out.println(m.values()[mmInt].name()); break; case 4: formattedMonth = "05"; //System.out.println(m.values()[mmInt].name()); break; case 5: formattedMonth = "06"; //System.out.println(m.values()[mmInt].name()); break; case 6: formattedMonth = "07"; //System.out.println(m.values()[mmInt].name()); break; case 7: formattedMonth = "08"; //System.out.println(m.values()[mmInt].name()); break; case 8: formattedMonth = "09"; //System.out.println(m.values()[mmInt].name()); break; case 9: formattedMonth = "10"; //System.out.println(m.values()[mmInt].name()); break; case 10: formattedMonth = "11"; //System.out.println(m.values()[mmInt].name()); break; case 11: formattedMonth = "12"; //System.out.println(m.values()[mmInt].name()); break; } if (year%4==0) //leap year { objectLeapYearFebruaryDays = m.FEB.days; // obtain number days from enum intLeapYearFebruaryDays = (int) (objectLeapYearFebruaryDays)+1; //increase by 1 leapYear=true; //flag set to true } //System.out.println("This is the month:" + m.name()); days = m.days; if (m.name()=="FEB" && leapYear) { days = (Object) intLeapYearFebruaryDays; // this is officially setting days as 29 } daysMonth = (int) days; if (processedFirstMonth) { ddInt=1; //will ensure second month will start from first day DD } //moving through days for (int k=ddInt; k<=(int) daysMonth; k++) { month = m.month; //setting month object to enum variable month.... i.e JAN, FEB temp=""; // clearing value from temp temp = Integer.toString(k); if (k<10) { //temp will store DD if day of month is less than 10 temp = prefixZero.toString() + Integer.toString(k); } //System.out.println("This is the day: " + temp); finalDate = temp + "/" + formattedMonth + "/" + year; //full DD/MM/YYYY finalDatePalindrome = temp + formattedMonth + year; //DDMMYYYY //System.out.println("This is final date: " + finalDate); checkPalindrome(finalDate, finalDatePalindrome); // method call //System.out.println(temp); //System.out.println(formattedMonth); if (k==daysMonth && formattedMonth=="12") // if it reached last day month of December { year++; // increase the year mmInt=0; // this starts again new year.. 0 since used in zero index scenarios... newYearRollOver=true; //sets flag new year } } processedFirstMonth=true; if (!newYearRollOver) // this now deals with all other scenarios of increasing month { mmInt=mmInt+1; } } monthcount++; }while(monthcount<=12); //year++; //System.out.println("YEAR IS NOW:$$$$ " + year); } //return 1; } }