Binary search is sufficient for this particular case.
To help the explain, we assume the circular sorted array is ascending if
probably rotated. we use *d[0..n - 1]* to represent the array
with n elements and *v* to represent the searched number.
Observing the circular sorted sequence d[0..n - 1]:
Use ternary search to find the minimum number. (In this case 1)
Then you have two sorted arrays, one ascending and one descending.
Now, you can apply binary search. First, check the number with the
last element and the first element and chose the appropriate array for
searching.
Time complexity: O