# Number to Roman Numerals

Roman numbers are non-positional numbers. Some numerals are placed together to form a number in roman numbers. For an example the number 75 can be expressed as 75 = 50 + 10 + 10 + 5, so the roman numerals are LXXV.

In this problem one number is provided in a decimal format, our task is to convert it into the Roman numeral strings.

There are different symbols and their value, like this.

 I IV V IX X XL L XC C CD D CM M MMMM V’ 1 4 5 9 10 40 50 90 100 400 500 900 1000 4000 5000

Using this table, we can easily find the roman numerals of a given number.

## Input and Output

Input:
Decimal number: 3569
Output:
The Roman equivalent of 3569 is: MMMDLXIX

## Algorithm

decToRoman(nuList, num)

Input: The numeral list with its value, number to convert into roman.

Output: The Roman numerals for the given number.

Begin
if num ≠ 0, then
max := get maximum numeral value, not greater than number
display the nuList[max].symbol
num := num – nuList[max].value
decToRoman(nuList, num)
End

## Example

#include<iostream>
using namespace std;

struct numeral {
string sym;
int val;
};

int maxNume(numeral nu[], int num) {
int index;
for(int i = 0; i<15; i++)   //15 numerals in array
if(nu[i].val<= num)
index = i;
//gretest value numeral index, not greater than number
return index;
}

void decToRoman(numeral nu[], int num) {
int max;
if(num != 0) {
max = maxNume(nu, num);
cout << nu[max].sym;
num -= nu[max].val;   //decrease number
decToRoman(nu, num);   //recursively print numerals
}
}

int main() {
int number;
numeral nume = {{"I",1},{"IV",4},{"V",5},{"IX",9},
{"X",10},{"XL",40},{"L",50},{"XC",90},
{"C",100},{"CD",400},{"D",500},{"CM",900},
{"M",1000},{"MMMM",4000},{"V'",5000}
};
cout << "Enter a decimal number: "; cin >> number;

if(number >0 && number <= 5000) {   //checking input number
cout<<"The Roman equivalent of " << number<<" is: ";
decToRoman(nume, number);
}else {
cout << "Invalid Input";
}
}

## Output

Enter a decimal number: 3569
The Roman equivalent of 3569 is: MMMDLXIX 