Formula1(Front-end).js

// Place any jQuery/helper plugins in here.
function findUniq(arrayStr) {
    var firstElement = arrayStr[0]
    var secondElement = arrayStr[1]

    var result = charSet(firstElement);

    if (!isEqualSet(result, charSet(secondElement))) {
        var thirdElement = arrayStr[2]
        if (isEqualSet(result, charSet(thirdElement))) {
            return secondElement;
        } else {
            return firstElement;
        }
    }
    arrayStr = arrayStr.slice(2);
    res = arrayStr.find((element) => {
        var tmpSet = charSet(element);
        var tmpResult = isEqualSet(result, tmpSet)
        return !tmpResult
    });
    return res;
}

function charSet(string) {
    //Use memoization for this function
    if (!charSet.cache)
        charSet.cache = {};

    if (!charSet.cache[string]) {
        charSet.cache[string] = new Set(string.replace(/ /g, '').split(''));
    }
    return charSet.cache[string]
};

function isEqualSet(setA, setB) {
    if (setA.size !== setB.size) {
        return false;
    }
    for (let value of setA) {
        if (!setB.has(value)) {
            return false;
        }
        return true;
    }
    return true;
}