0033-search-in-rotated-sorted-array.java

class Solution {

    public int search(int[] nums, int target) {
        int minIndex = minIndex(nums);
        int leftSearch = binarySearch(nums, 0, minIndex - 1, target);
        int rightSearch = binarySearch(nums, minIndex, nums.length - 1, target);
        if (leftSearch != -1) {
            return leftSearch;
        } else if (rightSearch != -1) {
            return rightSearch;
        } else {
            return -1;
        }
    }

    public int minIndex(int[] nums) {
        int start = 0;
        int end = nums.length - 1;
        while (start <= end) {
            int mid = start + (end - start) / 2;
            int prev = (mid - 1 + nums.length) % nums.length;
            int next = (mid + 1) % nums.length;
            if (nums[mid] <= nums[prev] && nums[mid] <= nums[next]) {
                return mid;
            } else if (nums[mid] <= nums[end]) {
                end = mid - 1;
            } else if (nums[mid] >= nums[start]) {
                start = mid + 1;
            }
        }
        return -1;
    }

    public int binarySearch(int[] nums, int start, int end, int target) {
        while (start <= end) {
            int mid = start + (end - start) / 2;
            if (nums[mid] == target) {
                return mid;
            } else if (nums[mid] < target) {
                start = mid + 1;
            } else {
                end = mid - 1;
            }
        }
        return -1;
    }
}