MaxProductOfThree.md

Task description A non-empty zero-indexed array A consisting of N integers is given. The product of triplet (P, Q, R) equates to A[P] * A[Q] * A[R] (0 ≤ P < Q < R < N).

For example, array A such that:

  A[0] = -3
  A[1] = 1
  A[2] = 2
  A[3] = -2
  A[4] = 5
  A[5] = 6

contains the following example triplets:

(0, 1, 2), product is −3 * 1 * 2 = −6 (1, 2, 4), product is 1 * 2 * 5 = 10 (2, 4, 5), product is 2 * 5 * 6 = 60 Your goal is to find the maximal product of any triplet.

Write a function:

function solution(A);

that, given a non-empty zero-indexed array A, returns the value of the maximal product of any triplet.

For example, given array A such that:

  A[0] = -3
  A[1] = 1
  A[2] = 2
  A[3] = -2
  A[4] = 5
  A[5] = 6

the function should return 60, as the product of triplet (2, 4, 5) is maximal.

Assume that:

N is an integer within the range [3..100,000]; each element of array A is an integer within the range [−1,000..1,000]. Complexity:

expected worst-case time complexity is O(N*log(N)); expected worst-case space complexity is O(1), beyond input storage (not counting the storage required for input arguments). Elements of input arrays can be modified.

function solution(A) {
    A.sort((a, b) => (a - b));

    return Math.max(A[A.length - 1] * A[A.length - 2] * A[A.length - 3], A[A.length - 1] * A[0] * A[1]) ;
}