Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

(i.e.,0 1 2 4 5 6 7might become4 5 6 7 0 1 2).

Write a function to determine if a given target is in the array.

The array may contain duplicates.

worst case is O(n), like 11111111

tag: binary search

class Solution {
    public boolean search(int[] nums, int target) {
        int start = 0, end = nums.length - 1;

        while (start <= end){
            int mid = start + (end - start) / 2;

            if (nums[mid] == target) return true;

            // left part is sorted
            if (nums[start] < nums[mid]){
                if (target < nums[start] || target > nums[mid]){
                    start = mid + 1;
                }
                else{
                    end = mid - 1;    
                }
            }
            // right part is sorted
            else if (nums[start] > nums[mid]){
                if (target > nums[end] || target < nums[mid]){
                    end = mid - 1;
                }
                else{
                    start = mid + 1;
                }
            }
            // nums[mid] != target
            // nums[start] == nums[mid]
            // means found duplicates
            else{
                start++;
            }
        }   

        return false;     
    }
}