readme.md

Challenge: Symmetric Difference Challenge

Instructions

We'll start with a pretty simple challenge. Write a function called symmetricDifference that takes in two arrays and returns an array containing the symmetric difference of the two arrays. The symmetric difference of two arrays is a new array containing only the elements that are present in one of the arrays but not both, with no duplicates.

Function Signature

/**
 * Returns an array containing the symmetric difference of two arrays.
 * @param {number[]} arr1 - The first array of integers.
 * @param {number[]} arr2 - The second array of integers.
 * @returns {number[]} - The array containing the symmetric difference of the two arrays.
 */
function symmetricDifference(arr1: number[], arr2: number[]): number[]

Examples

symmetricDifference([1, 2, 3], [3, 4, 5]);
// Output: [1, 2, 4, 5]

symmetricDifference([1, 2, 2, 3, 4], [2, 3, 3, 4, 5]);
// Output: [1, 5]

symmetricDifference([1, 2, 3, 4, 5], [5, 4, 3, 2, 1]);
// Output: []

symmetricDifference([1, 2, 3], [4, 5, 6]);
// Output: [1, 2, 3, 4, 5, 6]

Hints

• You can use two Sets to keep track of elements in both arrays and then find the elements that are present in only one of the sets.
• Be mindful of duplicate elements and handle them appropriately.

Solutions

Click For Solution

function symmetricDifference(arr1, arr2) {
  const set1 = new Set(arr1);
  const set2 = new Set(arr2);
  const result = [];

  for (const num of arr1) {
    if (!set2.has(num)) {
      result.push(num);
    }
  }

  for (const num of arr2) {
    if (!set1.has(num)) {
      result.push(num);
    }
  }

  return result;
}

Explanation

• To find the symmetric difference, create two Set objects, set1 and set2, from arr1 and arr2 respectively. The Set data structure allows us to efficiently check for the existence of an element.
• Initialize an empty array called result to store the symmetric difference.
• Iterate through each element in arr1 using a for...of loop. For each element in arr1, we use the has() method of set2 to check if the element exists in set2. If the element is not found in set2, it means it is present in arr1 but not in arr2, and push it into the result array.
• Similarly, iterate through each element in arr2 using another for...of loop. For each element in arr2, we use the has() method of set1 to check if the element exists in set1. If the element is not found in set1, it means it is present in arr2 but not in arr1, and push it into the result array.
• Return the result array, which contains the elements that are present in only one of the input arrays, with no duplicates.

Test Cases

test('Symmetric Difference of Two Arrays', () => {
  expect(symmetricDifference([1, 2, 3], [3, 4, 5])).toEqual([1, 2, 4, 5]);
  expect(symmetricDifference([1, 2, 2, 3, 4], [2, 3, 3, 4, 5])).toEqual([1, 5]);
  expect(symmetricDifference([1, 2, 3, 4, 5], [5, 4, 3, 2, 1])).toEqual([]);
  expect(symmetricDifference([1, 2, 3], [4, 5, 6])).toEqual([1, 2, 3, 4, 5, 6]);
});