033. Search in Rotated Sorted Array

 1 class Solution {
 2 public:
 3     int search(vector<int>& nums, int target) {
 4         if (nums.size() == 0) return -1;
 5         else {
 6             int left = 0, right = nums.size() - 1;
 7             while (left <= right) {
 8                 int mid = left + (right - left) / 2;
 9                 //cout << "left = " << left << ‘\t‘ << "right = " << right << endl;
10                 if (nums[mid] == target) return mid;
11                 else if (nums[mid] < target) {
12                     if (nums[mid] < nums[right]) {
13                         if (nums[right] == target) return right;
14                         else if (nums[right] < target) right = mid - 1;
15                         else left = mid + 1;
16                     }
17                     else {
18                         left = mid + 1;
19                     }
20                 }
21                 else {
22                     if (nums[mid] < nums[right]) right = mid - 1;
23                     else {
24                         if (nums[left] == target) return left;
25                         else if (nums[left] < target) right = mid - 1;
26                         else  left = mid + 1;
27                     }
28                 }
29             }
30             return -1;
31         }
32     }
33 };