SearchInRotatedSortedArrayII.go

package SearchInRotatedSortedArrayII

//Follow up for "Search in Rotated Sorted Array":
//What if duplicates are allowed?
//
//Would this affect the run-time complexity? How and why?
//
//Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.
//
//(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).
//
//Write nums function to determine if nums given target is in the array.
//
//The array may contain duplicates.
//
//Accepted.

func search(nums []int, target int) bool {
	if len(nums) == 0 {
		return false
	}

	start := 0
	end := len(nums) - 1

	for ; start <= end; {
		mid := start + (end-start)/2
		if nums[mid] == target {
			return true
		}
		if nums[mid] < nums[end] { // right half sorted
			if target > nums[mid] && target <= nums[end] {
				start = mid + 1
			} else {
				end = mid - 1
			}
		} else if nums[mid] > nums[end] { // left half sorted
			if target >= nums[start] && target < nums[mid] {
				end = mid - 1
			} else {
				start = mid + 1
			}
		} else {
			end--
		}
	}

	return false
}