1.题目： 

 

 

2.解析：

 

代码：

方法一：以最后一个元素为参照物int left = 0, right = nums.length-1;int n = nums.length-1;while(left < right) {int mid = left+(right-left)/2;if(nums[mid] > nums[n]) left = mid+1;else right = mid;}return nums[left];//方法二：以第一个元素为参照物int left = 0, right = nums.length-1;int min = 0;while(left < right) {int mid = left+(right-left)/2;if(nums[mid] < nums[0]) right = mid;else left = mid+1;}min = nums[left];return min > nums[0] ? nums[0] : min;