import java.util.*; public class Solution { public static void main (String []args) { for (int i=1; i<=4000; i++) { System.out.println("Decimal: " + i + " => " + decimalToRoman(i)); } } //NUMERALS numeral = NUMERAL.1000.value(); public static String decimalToRoman(int num) { String beyondIncorrectNumeral=""; String temp=""; boolean executeOnce=false; boolean hasIncorrectNumeral=true; String conversion=""; int currentNumeral=0; int match=0; char fourInRowNumeral=' '; char incorrectPredecessor=' '; String successor=""; String [] nextHighest = new String[6]; nextHighest[0] = "I=>V"; nextHighest[1] = "V=>X"; nextHighest[2] = "X=>L"; nextHighest[3] = "L=>C"; nextHighest[4] = "C=>D"; nextHighest[5] = "D=>M"; String [] numerals = new String[]{"I","V","X","L","C","D","M"}; //M=1000, C=100, D=500, L=50, X=10, V=5, I=1 //these have to be descending order //return "test"; //I will first attempt this from recursive perspective.. //using a class level variable //This should much easier than conversion numeral => decimal number //we only need to worry about the valid subtractive notations (as a pair) //do not need to worry about adjacent subtractive notation being in the same range //not relevant //i.e IX XC //range (1-10) (range 10-100) // these are the valid combinations.... //String IV = "IV"; //String IX = "IX"; //String XL = "XL"; //String XC = "XC"; //String CD= "CD"; //String CM= "CM"; //Also need to consider this rule //The xcletters V, L, and D are not repeated. //I will work this example using the following two numbers //27 and also 19 //both will bring their own challenges //main structure of code if (num==0) { return conversion; } else { //M=1000, C=100, D=500, L=50, X=10, V=5, I=1 //only way to tackle this challenge is using an if else //and check if larger than numbers //1000, 500, 100, 50, 10, 5 , 1 //Map will not work!!! //Switch will not work!!! //So similar to numeral => decimal, there will be no collections!!!!! //do //{ do { if (num >= 1000) { currentNumeral++; conversion = conversion + "M"; num=num-1000; //System.out.println("num is greater than: " + 1000); } else if (num>=500) { currentNumeral++; conversion = conversion + "D"; num=num-500; //System.out.println("num is greater than: " + 500); } else if (num>=100) { currentNumeral++; conversion = conversion + "C"; num=num-100; //System.out.println("num is greater than: " + 100); } else if (num>=50) { currentNumeral++; conversion = conversion + "L"; num = num - 50; //System.out.println("num is greater than: " + 50); } else if (num>=10) { currentNumeral++; conversion = conversion + "X"; num = num -10; //System.out.println("num is greater than: " + 10); } else if (num>=5) { currentNumeral++; conversion = conversion + "V"; num = num - 5; //System.out.println("num is greater than: " + 5); } else if (num>=1) { currentNumeral++; conversion = conversion + "I"; num = num - 1; //System.out.println("num is greater than: " + 1); } else { } } while (num>0); System.out.println(conversion); if (conversion.indexOf("MCCCC")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("MCCCC")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("MCCCC")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("MCCCC")).length()>0) { temp = conversion.substring(0,conversion.indexOf("MCCCC")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "MCD" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "MCD" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("DCCCC")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("DCCCC")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("DCCCC")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("DCCCC")).length()>0) { temp = conversion.substring(0,conversion.indexOf("DCCCC")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "CM" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "CM" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("CCCC")!=-1) { if(conversion.length()>4) { conversion = "CD" + conversion.substring(conversion.indexOf("CCCC")+4); } else { conversion = "CD"; } } //System.out.println("------------------------------"); if (conversion.indexOf("MXXXX")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("MXXXX")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("MXXXX")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("MXXXX")).length()>0) { temp = conversion.substring(0,conversion.indexOf("MXXXX")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "MXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "MXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("DXXXX")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("DXXXX")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("DXXXX")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("DXXXX")).length()>0) { temp = conversion.substring(0,conversion.indexOf("DXXXX")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "DXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "DXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } //********************************8 if (conversion.indexOf("CXXXX")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("CXXXX")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("CXXXX")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("CXXXX")).length()>0) { temp = conversion.substring(0,conversion.indexOf("CXXXX")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "CXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "CXL" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("LXXXX")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("LXXXX")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("LXXXX")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("LXXXX")).length()>0) { temp = conversion.substring(0,conversion.indexOf("LXXXX")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "XC" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "XC" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("XXXX")!=-1) { if(conversion.length()>4) { conversion = "XL" + conversion.substring(conversion.indexOf("XXXX")+4); System.out.println("Processes if"); } else { System.out.println("Processes else"); conversion = "XL"; } } //System.out.println("------------------------------"); if (conversion.indexOf("MIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("MIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("MIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("MIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("MIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "MIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "MIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("DIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("DIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("DIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("DIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("DIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "DIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "DIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("CIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("CIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("CIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("CIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("CIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "CIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "CIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("LIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("LIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("LIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("LIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("LIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "LIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "LIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("XIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("XIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("XIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("XIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("XIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "XIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "XIV" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } if (conversion.indexOf("VIIII")!=-1) { //System.out.println("THIS PATTERN"); //System.out.println("Last index Conversion: " + (conversion.length()-1)); //System.out.println(conversion.indexOf("VIIII")+4); //System.out.println("Length string before the match: " + conversion.substring(0,conversion.indexOf("VIIII")).length()); if (conversion.indexOf("VIIII")!=-1) { //if more characters beyond last X of LXXXX if ((conversion.indexOf("VIIII")+4)!=conversion.length()-1) { beyondIncorrectNumeral = conversion.substring(conversion.indexOf("VIIII")+5); } //if more characters in front if (conversion.substring(0,conversion.indexOf("VIIII")).length()>0) { temp = conversion.substring(0,conversion.indexOf("VIIII")); //System.out.println("SHOULD BE HERE IF STATEMENT"); conversion = temp + "IX" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } else { //System.out.println("SHOULD BE HERE ELSE STATEMENT"); conversion = "IX" + beyondIncorrectNumeral; //System.out.println("original => conversion: " + temp + " => " + conversion); } beyondIncorrectNumeral=""; } } String [][] numeralsCorrection = new String[][]{ {"IIII","IV"},{"VIIII","IX"},{"XIIII","XIV"}, {"LIIII","LIV"},{"CIIII","CIV"},{"DIIII","DIV"},{"MIIII","MIV"}, {"XXXX","XL"},{"LXXXX","XC"},{"XIIII","XIV"}, {"LIIII","LIV"},{"CIIII","CIV"},{"DIIII","DIV"},{"MIIII","MIV"}, }; if (conversion.indexOf("IIII")!=-1) { //we can not use this logic here, since it will evalulate as 0. //And performing substring as this as delimiter will match the start //and give StringIndexOutOfBoundsException //if (conversion.substring(0,conversion.indexOf("IIIII")).length()>0) if(conversion.length()>4) { System.out.println("IF STATEMENT"); conversion = "IV" + conversion.substring(conversion.indexOf("IIII")+4); } else { System.out.println("ELSE STATEMENT"); conversion = "IV"; } } //System.out.println("------------------------------"); //we need to address each scenario from the most left hand side first //I do not think it will matter either way... /* if m before CCCC => MCD (MCD) if d before CCCC => CM (CM) if nothing before CCCC => CD (CD) if M before XXXX => MXL (MXL) if D before XXXX => DXL (DXL) if C before XXXX => CXL (CXL) if L before XXXX => XC (XC) if nothing before XXXX => XL (XL) if D before IIII => D followed by IV (DIV) if L before IIII => L followed by IV (LIV) if X before IIII => X followed by IV (XIV) if V before IIII => I followed by next highest letter to V (IX) if nothing before IIII => (IV) */ } //end of else return conversion; } }