Array rotation. Given an array of n elements, give a linear-time algorithm to rotate the string k positions. That is, if the array contains a 0 , a 1 , …, a n-1 , the rotated array is a k ,  k+1 , …,...

Array rotation. Given an array of n elements, give a linear-time algorithm to rotate the string k positions. That is, if the array contains a₀, a₁, …, a_n-1
, the rotated array is a_k,
_k+1, …, a_n-1, a₀, …, a_k-1. Use at most a constant amount of extra memory. Hint: Reverse three subarrays.