Write a function named nextPermutation that accepts an array of integers and rearranges its elements into the next permutation of that array's values in numerical order.
For example, consider the array [1, 2, 3].
The permutations of this array, arranged in numerical order, are:
[1, 2, 3]
[1, 3, 2]
[2, 1, 3]
[2, 3, 1]
[3, 1, 2]
[3, 2, 1]
So if your function were called and passed the array [2, 1, 3], you would rearrange it to [2, 3, 1], which is the next permutation listed above.
If you are passed the last permutation in numerical order, [3, 2, 1], rearrange it into the first permutation, [1, 2, 3].
As another example, if passed [1, 2, 7, 8, 6, 5, 4, 3], your function should modify the array to store [1, 2, 8, 3, 4, 5, 6, 7].
