33-Search-in-Rotated-Sorted-Array.java

class Solution {
    public int search(int[] nums, int target) {
        int pivot = findPivot(nums);

        if(pivot == -1) {
            return binarySearch(nums, target, 0, nums.length - 1);
        } else if(nums[pivot] == target) {
            return pivot;
        } else if(nums[0] <= target) {
            return binarySearch(nums, target, 0, pivot);
        } else {
            return binarySearch(nums, target, pivot+1, nums.length - 1);
        }
    }

    public int findPivot(int[] nums) {
        int start = 0;
        int end = nums.length - 1;

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

            if(mid < end && nums[mid] > nums[mid+1]) {
                return mid;
            } else if(mid > start && nums[mid] < nums[mid-1]) {
                return mid-1;
            } else if(nums[start] < nums[mid]) {
                start = mid + 1;
            } else {
                end = mid - 1;
            }
        }
        return -1;
    }

    public int binarySearch(int[] nums, int target, int start, int end) {
        while(start <= end) {
            int mid = start + (end - start)/2;

            if(nums[mid] == target) {
                return mid;
            } else if(nums[mid] > target) {
                end = mid - 1;
            } else {
                start = mid + 1;
            }
        }
        return -1;
    }
}