Question:

Converting Roman Number to Integer

Summary:

Given a string in roman no format (s) your task is to convert it to an integer . Various symbols and their values are given below.

I 1

V 5

X 10

L 50

C 100

D 500

M 1000

Solution:

//User function Template for javascript

/**

* @param {string} str

* @returns {number}

class Solution {

romanToDecimal(str){

const romanNumerals = {

M: 1000,

CM: 900,

D: 500,

CD: 400,

C: 100,

XC: 90,

L: 50,

XL: 40,

X: 10,

IX: 9,

V: 5,

IV: 4,

I: 1,

};

let result = 0;

for (let i = 0; i < str.length; i++) {

const currentSymbol = str[i];

const nextSymbol = str[i + 1];

if (romanNumerals[currentSymbol] < romanNumerals[nextSymbol]) {

result -= romanNumerals[currentSymbol];

} else {

result += romanNumerals[currentSymbol];

}

return result;

}

The provided JavaScript code defines a class Solution with a method romanToDecimal. This method takes a Roman numeral represented as a string (str) and converts it to its decimal equivalent.

Code Explanation:

Create an object ‘romannumerals’ that maps Roman numeral symbols to their decimal values.
Initialize a variable result to 0, which will store the final decimal value.
Iterate through each character in the input string (str).
For each character, check its value in the “romanNumerals” object.
Compare the current symbol with the next symbol. If the current symbol has a smaller value than the next symbol, subtract the current symbol's value from the result (e.g., IV represents 4, where I is subtracted from V).
If the current symbol is not smaller than the next symbol, add its value to the result.
Continue the loop until all characters in the string are processed.
Return the final result, which represents the decimal equivalent of the input Roman numeral.
The code follows the rules of Roman numeral representation, where certain combinations of symbols are used to represent specific values. The algorithm iterates through the input string, adjusting the result based on the comparison of adjacent symbols to handle cases where subtraction is required.