LeetCode.153

153. Find Minimum in Rotated Sorted Array

Suppose an array sorted in ascending order 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.

You may assume no duplicate exists in the array.

int half(vector<int>& nums, int begin, int end){
	if(begin == end){
		return nums[begin];
	}
	if(nums[begin] < nums[end]){
		return nums[begin];
	}
	else{
		int p = (begin + end) / 2;
		if(nums[begin] <= nums[p]){
			return half(nums, p + 1, end);
		}
		else{
			return half(nums, begin, p);
		}
	}
}

int findMin(vector<int>& nums){
	if(nums.empty()){
		return -1;
	}
	return half(nums, 0, nums.size() - 1);
}