☆打卡算法☆LeetCode 33、搜索旋转排序数组 算法解析

示例 1：
输入： nums = [4,5,6,7,0,1,2], target = 0
输出： 4

示例 2：
输入： nums = [4,5,6,7,0,1,2], target = 3
输出： -1

public class Solution 
{
    /// <summary>
    /// 旋转数组二分查找
    /// </summary>
    public int Search(int[] nums, int target)
    {
        int left = 0;
        int right = nums.Length - 1;
        while (left <= right)
        {
            int mid = left + (right - left) / 2;
            if (nums[mid] == target) return mid;
            if (nums[left] == target) return left;
            if (nums[right] == target) return right;

            if (target > nums[right])//target位于第1数组
            {
                if (nums[mid] > nums[right])//mid也位于第1数组
                {
                    if (nums[mid] < target) left = mid + 1;
                    else if (nums[mid] > target) right = mid - 1;
                }
                else right = mid - 1; //mid位于第2数组，肯定比target小，右侧直接舍去
            }
            else//target位于第2数组
            {
                if (nums[mid] > nums[right]) left = mid + 1;//mid位于第1数组，肯定比target大，左侧直接舍去
                else//mid也位于第2数组
                {
                    if (nums[mid] < target) left = mid + 1;
                    else if (nums[mid] > target) right = mid - 1;
                }
            }
        }
        return -1;
    }   
}