alg10-sortedUnion.js

const assert = require('assert');
/*
Source: <https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/intermediate-algorithm-scripting/sorted-union>

Sorted Union
Write a function that takes two or more arrays and returns a new array of unique values in the order of the original provided arrays.

In other words, all values present from all arrays should be included in their original order, but with no duplicates in the final array.

The unique numbers should be sorted by their original order, but the final array should not be sorted in numerical order.

Check the assertion tests for examples.
*/
function myUniteUnique(...arr) {
  return arr.reduce((newArr, currArr) => {
    const uniteUniqueArr = currArr.filter((num) => !newArr.includes(num));
    return newArr.concat(uniteUniqueArr);
  }, []);
}

assert.deepStrictEqual(myUniteUnique([1, 3, 2], [5, 2, 1, 4], [2, 1]), [1, 3, 2, 5, 4]);
assert.deepStrictEqual(myUniteUnique([1, 2, 3], [5, 2, 1]), [1, 2, 3, 5]);
assert.deepStrictEqual(myUniteUnique([1, 2, 3], [5, 2, 1, 4], [2, 1], [6, 7, 8]), [1, 2, 3, 5, 4, 6, 7, 8]);
/*
Get a help > Get a hint <>
*/
//Solution 1
function uniteUnique1(arr1, arr2, arr3) {
  // Creates an empty array to store our final result.
  var finalArray = [];

  // Loop through the arguments object to truly make the program work with two or more arrays
  // instead of 3.
  for (var i = 0; i < arguments.length; i++) {
    var arrayArguments = arguments[i];

    // Loops through the array at hand
    for (var j = 0; j < arrayArguments.length; j++) {
      var indexValue = arrayArguments[j];

      // Checks if the value is already on the final array.
      if (finalArray.indexOf(indexValue) < 0) {
        finalArray.push(indexValue);
      }
    }
  }

  return finalArray;
}

//Solution 2
function uniteUnique2(arr) {
  var args = [...arguments];
  var result = [];
  for (var i = 0; i < args.length; i++) {
    for (var j = 0; j < args[i].length; j++) {
      if (!result.includes(args[i][j])) {
        result.push(args[i][j]);
      }
    }
  }
  return result;
}

//Solution 3
function uniteUnique3(arr1, arr2, arr3) {
  var newArr;
  //Convert the arguments object into an array
  var args = Array.prototype.slice.call(arguments);
  //Use reduce function to flatten the array
  newArr = args.reduce(function(arrA, arrB) {
    //Apply filter to remove the duplicate elements in the array
    return arrA.concat(
      arrB.filter(function(i) {
        return arrA.indexOf(i) === -1;
      })
    );
  });

  return newArr;
}

//Solution 4
function uniteUnique4() {
  var concatArr = [];
  var i = 0;
  while (arguments[i]) {
    concatArr = concatArr.concat(arguments[i]);
    i++;
  }
  uniqueArray = concatArr.filter(function(item, pos) {
    return concatArr.indexOf(item) == pos;
  });
  return uniqueArray;
}

//Solution 5
function uniteUnique5(...arrays) {
  //make an array out of the given arrays and flatten it (using the spread operator)
  const flatArray = [].concat(...arrays);

  // create a Set which clears any duplicates since it's a regular set and not a multiset
  return [...new Set(flatArray)];
}

//Solution 6
function uniteUnique6(...arr) {
  return [...new Set(arr.flat())]
}