Progreamming Converting Arabic numbers to Roman

I'm saying both. You can't use cin.get and cin.peek because the next inputed numeral is very important. You are missing a concept or analiseing your problem and how to deide it into steps so you can implement it.

This would be my code for converting arabic to roman:

#include<string>
#include <iostream>

using namespace std;

int main()
{
string roman_Numeral;
int arabic_Numeral;
string numerals = "IVXLCDM"; //roman numerals
int index; //index for steping throu top string
int digit; //variable for digit conversion
string roman_digit;

while(1){ //endless loop, good for seing all the input and brakeing when input is not a positive number

cout << "Enter the number you want to convert to roman (0 or negative to exit) : ";
cin>>arabic_Numeral
if(arabic_Numeral<1) break;

roman_Numeral="";
index=0;
while(arabic_Numeral!=0){ //the algoritym for conversion
digit=arabic_Numeral%10; //take the last digit
arabic_Numeral/=10; //leave all the other digits
switch(digit){ //convert digit here depending on the index we know in what range the number is.
case 0:
roman_digit="";
break;
case 1:
roman_digit=numerals[index];
break;
case 2:
roman_dgigit=numerals[index]+numerals[index];
break;
case 3:
roman_digit=numerals[index]+numerals[index]+numerals[index];
break;
case 4:
roman_digit=numerals[index]+numerals[index+1];
break;
case 5:
roman_digit=numerals[index+1];
break;
case 6:
roman_digit=numerals[index+1]+numerals[index];
break;
case 7:
roman_digit=numerals[index+1]+numerals[index]+numerals[index];
break;
case 8:
roman_digit=numerals[index+1]+numerals[index]+numerals[index]+numerals[index];
break;
case 9:
roman_digit=numerals[index]+numerals[index+2];
break;
default:
roman_digit="";
break;
}
roman_Numeral=roman_digit+roman_Numeral; //add the new digit to the previously calculated ones
index+=2; //increes the index to know where to look in the roman digit string

if(index>5){ //only will activate if number is greater than 1000
while(arabic_Numeral!=0){ //all else is just adding the correct count of 'M' in front.
roman_Numeral="M"+roman_Numeral;
arabic_Numeral--;
}
}
}

cout<<"Your roman numeral is: "+roman_Numeral;

}
return 1;
}


Even if it seems like a simple conversion, you must break the process into logical parts. You can allmost never reuse the same code for backward conversion, so you will allways have to make a new algorythm (code).