Java Coding Problems

105. Reversing an array

There are several solutions to this problem. Some of them mutate the initial array, while others just return a new array.

Let's assume the following array of integers:

int[] integers = {-1, 2, 3, 1, 4, 5, 3, 2, 22};

Let's start with a simple implementation that swaps the first element of the array with the last element, the second element with the penultimate element, and so on:

public static void reverse(int[] arr) {  for (int leftHead = 0, rightHead = arr.length - 1;       leftHead < rightHead; leftHead++, rightHead--) {    int elem = arr[leftHead];    arr[leftHead] = arr[rightHead];    arr[rightHead] = elem;  }}

The preceding solution mutates the given array and this is not always the desired behavior. Of course, we can modify ...