Javascript Algorithm:Symmetric Difference between multiple sets(FreeCodeCamp)

Find the Symmetric Difference:

The mathematical term symmetric difference (△ or ⊕) of two sets is the set of

elements which are in either of the two sets but not in both. For example, for

sets A = {1, 2, 3} and B = {2, 3, 4}, A △ B = {1, 4}.

Symmetric difference is a binary operation, which means it operates on only two

elements. So to evaluate an expression involving symmetric differences among

three elements (A △ B △ C), you must complete one operation at a time. Thus, for

sets A and B above, and C = {2, 3}, A △ B △ C = (A △ B) △ C = {1, 4} △ {2, 3} =

{1, 2, 3, 4}.

Create a function that takes two or more arrays and returns an array of their

symmetric difference. The returned array must contain only unique values (no

duplicates).

Test Cases:

1) sym([1, 2, 3], [5, 2, 1, 4]) should return [3, 4, 5].

2) sym([1, 2, 3], [5, 2, 1, 4]) should contain only three elements.

3) sym([1, 2, 3, 3], [5, 2, 1, 4]) should return [3, 4, 5].

4) sym([1, 2, 3, 3], [5, 2, 1, 4]) should contain only three elements.

5) sym([1, 2, 3], [5, 2, 1, 4, 5]) should return [3, 4, 5].

6) sym([1, 2, 3], [5, 2, 1, 4, 5]) should contain only three elements.

7) sym([1, 2, 5], [2, 3, 5], [3, 4, 5]) should return [1, 4, 5].

8) sym([1, 2, 5], [2, 3, 5], [3, 4, 5]) should contain only three elements.

9) sym([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5]) should return [1, 4, 5].

10) sym([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5]) should contain only three

elements.

11) sym([3, 3, 3, 2, 5], [2, 1, 5, 7], [3, 4, 6, 6], [1, 2, 3]) should return

[2, 3, 4, 6, 7].

12) sym([3, 3, 3, 2, 5], [2, 1, 5, 7], [3, 4, 6, 6], [1, 2, 3]) should contain

only five elements.

13) sym([3, 3, 3, 2, 5], [2, 1, 5, 7], [3, 4, 6, 6], [1, 2, 3], [5, 3, 9, 8],

[1]) should return [1, 2, 4, 5, 6, 7, 8, 9].

14) sym([3, 3, 3, 2, 5], [2, 1, 5, 7], [3, 4, 6, 6], [1, 2, 3], [5, 3, 9, 8],

[1]) should contain only eight elements.

Solution:

function BinarySymmetricDifference(a, b) {

let c = [...a, ...b];

//keep unique elements only

let set = new Set(c);

c = Array.from(set);

let d = [];

a.forEach((m) => {

if (b.includes(m)) {

if (!d.includes(m)) {

d.push(m);

}

}

});

let e = c.filter((m) => {

return !d.includes(m);

});

return e;

}

function sym(...args) {

let initialArray = args[0]

for (let i = 1; i < args.length; i++) {

initialArray = BinarySymmetricDifference(initialArray,args[i])

}

return initialArray

}

let diff = sym([1, 1, 2, 5], [2, 2, 3, 5], [3, 4, 5, 5]);

console.log(diff);