33. 搜索旋转排序数组

class Solution {
    public int search(int[] nums, int target) {
        int lo = 0;
        int hi = nums.length - 1;

        while (lo < hi) {
            int mid = (lo + hi) / 2;
            // 当[0,mid]有序时,向后规约条件
            if (nums[0] <= nums[mid] && (target > nums[mid] || target < nums[0])) {
                lo = mid + 1;
                // 当[0,mid]发生旋转时，向后规约条件
            } else if (target > nums[mid] && target < nums[0]) {
                lo = mid + 1;
            } else {
                hi = mid;
            }
        }
        return lo == hi && nums[lo] == target ? lo : -1;
    }
}

作者：breezean
链接：https://leetcode-cn.com/problems/search-in-rotated-sorted-array/solution/jian-ji-rong-yi-li-jie-java-er-fen-fa-by-breezean/
来源：力扣（LeetCode）
著作权归作者所有。商业转载请联系作者获得授权，非商业转载请注明出处。

class Solution {
public:
    int search(vector<int>& nums, int target) {
        int low =0;
        int high=nums.size()-1;
        while(low<high){
            int m=(low+high)/2;
            if((nums[0]>target)^(nums[0]>nums[m]^(target> nums[m])))low=m+1;
            else high=m;
        }
        return low==high&& nums[low]==target? low:-1;
    }
};