81.Search in Rotated Sorted Array II---二分变形

 1     public boolean search(int[] nums, int target) {
 2         int left = 0, right = nums.length - 1;
 3         while(left <= right) {
 4             int mid = (left + right) / 2;
 5             if(nums[mid] == target || nums[left] == target || nums[right] == target) {
 6                 return true;
 7             }
 8             //如果左数组有序
 9             else if(nums[left] < nums[mid]) {
10                 //如果target在左数组中
11                 if(target < nums[mid] && target > nums[left]) {
12                     right = mid - 1;
13                 }
14                 else {
15                     left = mid + 1;
16                 }
17             }
18             //如果右数组有序
19             else if(nums[mid] < nums[right]){
20                 //如果target在右数组中
21                 if(target < nums[right] && target > nums[mid]) {
22                     left = mid + 1;
23                 }
24                 else {
25                     right = mid - 1;
26                 }
27             }
28             //如果出现1,3,1,1,1的情况，mid值与left和right都相等，则将right--再比较
29             else {
30                 right--;
31             }
32         }
33         return false;
34     }