Given an array of integers arr, implement a function that returns the index of the number nearest to the given value n. If two numbers equally distant from n are found, the function will return the greatest of them.
nearestElement(10, [1, 100, 1000]) ➞ 0
// 1 is the number nearest to 10.
nearestElement(50, [100, 49, 51]) ➞ 2
// 49 and 51 are equally distant from 50, with 51 being the greatest.
nearestElement(-20, [-50, -10, -30]) ➞ 1
// -10 and -30 are equally distant from -20, with -10 being the greatest.
Integers in arr will always be unique.