Find Minimum in Rotated Sorted Array II

Suppose a sorted array is rotated at some pivot unknown to you beforehand.

(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).

Find the minimum element.

The array may contain duplicates.

解题思路:二分查找，首先由中点处查找不重复点

int Find(vector<int> &num, int first, int last){int mid = (first + last) / 2;int LeftIdx = mid;int RightIdx = mid;while (num[LeftIdx] == num[mid] && LeftIdx >= first)--LeftIdx;while (num[RightIdx] == num[mid] && RightIdx >= first)++RightIdx;if (LeftIdx<first){if (RightIdx>last)return num[mid];elsereturn min(num[mid], Find(num, RightIdx, last));}else{if (RightIdx > last)return min(num[mid], Find(num, first, LeftIdx));elsereturn min(Find(num, first, LeftIdx), min(Find(num, RightIdx, last),num[mid]));}}int findMin(vector<int> &num) {return Find(num, 0, num.size() - 1);}