Suppose an array of length `n` sorted in ascending order is rotated between `1` and `n` times. For example, the array `nums = [0,1,2,4,5,6,7]` might become: * `[4,5,6,7,0,1,2]` if it was rotated 4 times. * `[0,1,2,4,5,6,7]` if it was rotated 7 times. Notice that **rotating** an array `[a[0], a[1], a[2], ..., a[n-1]]` 1 time results in the array `[a[n-1], a[0], a[1], a[2], ..., a[n-2]]`. Given the sorted rotated array `nums` of **unique** elements, return *the minimum element of this array*. You must write an algorithm that runs in `O(log n)` time.