[LeetCode 33] Search in rotated

class Solution {
    public int search(int[] nums, int target) {
        if (nums == null || nums.length == 0) {
            return -1;
        }
        
        int start = 0;
        int end = nums.length - 1;
        
        while (start + 1 < end) {
            int middle = start + (end - start) / 2;
            
            if (nums [middle] == target)
                return middle;
            
            // [start - middle]: ascending order
            if (nums[start] < nums [middle]) {
                if (nums [start] <= target && target <= nums [middle]) {
                    end = middle;
                } else {
                    start = middle;
                }
            } else { // [middle - end]: ascending order
                if (nums [middle] <= target && target <= nums [end]) {
                    start = middle;
                } else {
                    end = middle;
                }
            }
        }
        
        if (nums [start] == target)
            return start;
        
        if (nums [end] == target)
            return end;
        
        return -1;
        
    }
}