SearchinRotatedSortedArray.cs

/*
There is an integer array nums sorted in ascending order (with distinct values).
Prior to being passed to your function, nums is possibly rotated at an unknown pivot index k (1 <= k < nums.length) such that the resulting array is [nums[k], nums[k+1], ..., nums[n-1], nums[0], nums[1], ..., nums[k-1]] (0-indexed). 
For example, [0,1,2,4,5,6,7] might be rotated at pivot index 3 and become [4,5,6,7,0,1,2].
Given the array nums after the possible rotation and an integer target, return the index of target if it is in nums, or -1 if it is not in nums.
You must write an algorithm with O(log n) runtime complexity.
*/
public class Solution {
    public int Search(int[] nums, int target) 
    {
        var left = 0;
        var right = nums.Length - 1;
        while(left <= right){
            var mid = left + (right - left) / 2;
            if(nums[mid] == target) return mid;
            if(nums[left] <= nums[mid]){
                if(nums[left] <= target && target < nums[mid]){
                    right = mid - 1;
                }
                else{
                    left = mid + 1;
                }
            }
            else{
                if(nums[mid] < target && target <= nums[right]){
                    left = mid + 1;
                }
                else{
                    right = mid - 1;
                }
            }
        }
        return -1;
    }
}