# Solved: int to roman

A Roman numeral is a numeral represented by a combination of letters from the Latin alphabet. These numerals, more prevalent during the reign of the Ancient Roman Empire, have now been mostly replaced by Arabic numerals. However, the representation of numbers as Roman numerals is a problem that still keeps popping up in the realm of computer science. In Java, we often need to convert an integer to its equivalent Roman numeral representation. In this article, we’re just going to delve into how to achieve that.

In order to convert an integer to its Roman numeral representation, we’re going to create a Java program. The program will take an integer input from the user and then return its equivalent Roman numeral.

Here’s the Java code that can be used to solve this problem:

```public class intToRoman {
static String intToRoman(int num) {
String[] m = {"", "M", "MM", "MMM"};
String[] c = {"", "C", "CC", "CCC", "CD", "D", "DC", "DCC", "DCCC", "CM"};
String[] x = {"", "X", "XX", "XXX", "XL", "L", "LX", "LXX", "LXXX", "XC"};
String[] i = {"", "I", "II", "III", "IV", "V", "VI", "VII", "VIII", "IX"};
String thousands = m[num/1000];
String hundreds = c[(num%1000)/100];
String tens = x[(num%100)/10];
String ones = i[num%10];
String ans = thousands + hundreds + tens + ones;
return ans;
}

public static void main(String[] args) {
int num = 2000;
System.out.println(intToRoman(num));
}
}
```

## Understanding the Java Program for Conversion

The Java program uses the concept of array indexing to solve this problem. The first step is the initialization of four arrays – ‘m’, ‘c’, ‘x’, and ‘i’. Each array represents the Roman numeral representation for different digits in the number.

The ‘m’ array represents the thousands place, the ‘c’ array represents the hundreds place, the ‘x’ represents the tens place, and the ‘i’ array represents the individual units place after division.

Now each of these arrays are filled with their Roman representations, and the correct Roman numeral is selected based on the array index that is calculated.

## Integating Java Libraries

Java libraries have been used in this code to facilitate the conversion. One of the most common Java library functions used is the ‘System.out.println()’ function from the ‘java.lang’ package. It is used for displaying output to the user.

Another widely employed library function is the ‘main()’ function, also part of the ‘java.lang’ package. This function is the entry point to any Java program.

## Practical Application of the Java Program

The conversion of integers to Roman numerals finds use in a number of applications. It is particularly useful in coding problems and tests where the ability to manipulate and represent data in different formats is tested. The understanding of this program can therefore be instrumental in solving not just this problem, but other similar problems as well.

From all these, we can conclude that the transformation of an integer to a Roman numeral using Java is a problem that can be easily tackled using array indexing and string handling mechanisms which Java readily and robustly provides.

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