diff-two-arrays.js

/**
 * Created by Hoan Nguyen on 11/11/2017.
 */

//Note that: this solution is for array of Intergers ONLY
function diffArray(arr1, arr2) {
	var output = [];
	// Same, same; but different.

	arr1.sort((a, b) => a - b);
	arr2.sort((a, b) => a - b);
	var i = 0, j = 0;

	while (true) {
		if (arr1[i] < arr2[j]) {
			output.push(arr1[i]);
			i++;
		} else if (arr1[i] > arr2[j]) {
			output.push(arr2[j]);
			j++;
		} else {
			i++;
			j++;
		}

		if (i == arr1.length && j == arr2.length) break;

		if (i == arr1.length && j < arr2.length) {
			for (var x = j; x < arr2.length; x++) {
				output.push(arr2[x]);
			}
			break;
		}

		if (j == arr2.length && i < arr1.length) {
			for (var y = i; y < arr1.length; y++) {
				output.push(arr1[y]);
			}
			break;
		}
	}


	return output;
}


function findDifference(arr1, arr2) {

	var a = Array.from(new Set(arr1));
	var b = Array.from(new Set(arr2));

	var map = new Map();
	var output = [];

	for (var i = 0; i < a.length; i++) {
		map.set(a[i], 1);
	}

	for (var i = 0; i < b.length; i++) {
		if (map.has(b[i])) {
			map.set(b[i], map.get(b[i]) + 1);
		} else {
			map.set(b[i], 1);
		}
	}

	var keys = Array.from(map.keys());
	for (var i = 0; i < keys.length; i++) {
		if (map.get(keys[i]) === 1) output.push(keys[i]);
	}
	return output;
}

// diffArray([1, 4, 3, 5], [1, 2, 3, 4, 5, 8]);
console.log(diffArray([1, 4, 3, 5, 10], [1, 2, 3, 4, 5, 8]));
// console.log(diffArray([1, 4, 3, 10], [1, 2, 3, 4, 5]));
console.log(findDifference([1, 4, 3, 5, 10], [1, 2, 2, 3, 4, 5, 8]));

console.log(findDifference(["diorite", "andesite", "grass", "dirt", "pink wool", "dead shrub"], ["diorite", "andesite", "grass", "dirt", "dead shrub"]));