#### Modular Arithmetic

H
```import { extendedEuclideanGCD } from './ExtendedEuclideanGCD'

/**
* https://brilliant.org/wiki/modular-arithmetic/
* @param {Number} arg1 first argument
* @param {Number} arg2 second argument
* @returns {Number}
*/

export class ModRing {
constructor (MOD) {
this.MOD = MOD
}

isInputValid = (arg1, arg2) => {
if (!this.MOD) {
throw new Error('Modulus must be initialized in the object constructor')
}
if (typeof arg1 !== 'number' || typeof arg2 !== 'number') {
throw new TypeError('Input must be Numbers')
}
}
/**
* Modulus is Distributive property,
* As a result, we separate it into numbers in order to keep it within MOD's range
*/

add = (arg1, arg2) => {
this.isInputValid(arg1, arg2)
return ((arg1 % this.MOD) + (arg2 % this.MOD)) % this.MOD
}

subtract = (arg1, arg2) => {
this.isInputValid(arg1, arg2)
// An extra MOD is added to check negative results
return ((arg1 % this.MOD) - (arg2 % this.MOD) + this.MOD) % this.MOD
}

multiply = (arg1, arg2) => {
this.isInputValid(arg1, arg2)
return ((arg1 % this.MOD) * (arg2 % this.MOD)) % this.MOD
}

/**
*
* It is not Possible to find Division directly like the above methods,
* So we have to use the Extended Euclidean Theorem for finding Multiplicative Inverse
* https://github.com/TheAlgorithms/JavaScript/blob/master/Maths/ExtendedEuclideanGCD.js
*/

divide = (arg1, arg2) => {
// 1st Index contains the required result
// The theorem may have return Negative value, we need to add MOD to make it Positive
return (extendedEuclideanGCD(arg1, arg2) + this.MOD) % this.MOD
}
}
```  