SearchInRotatedArray.java

class SearchInRotatedArray {
    public int search(int[] nums, int target) {
        return search(nums, 0, nums.length - 1, target);
    }

    private int search(int[] nums, int start, int end, int target) {
        if (start > end) return -1;
        int midIdx = start + (end - start) / 2;
        int mid = nums[midIdx];
        if (target == mid) return midIdx;
        int first = nums[start];
        int last = nums[end];
        if (first <= mid) {
            if (target < mid && first <= target) {
                return search(nums, start, midIdx - 1, target);
            } else {
                return search(nums, midIdx + 1, end, target);
            }
        } else {
            if (target > mid && last >= target) {
                return search(nums, midIdx + 1, end, target);
            } else {
                return search(nums, start, midIdx - 1, target);
            }
        }
    }
}