在无重复数字的循环数组中查找给定数返回其下标

在无重复数字的循环数组中查找给定数，返回其下标

/*在无重复数字的循环数组中查找给定数，返回其下标
 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).
You are given a target value to search. If found in the array return its index, otherwise return -1.
You may assume no duplicate exists in the array. 
*/

#include
#include
#include
#include
using namespace std;

class Solution
{
public:
int search(int A[], int n, int target)
{
        if(A==nullptr || n==0)
			return -1;
        int left=0,right=n-1;
        while(left <= right)			//终止条件
		{
            int mid=(left+right)/2;		//中间位置
            if (A[mid]==target)
				return mid;
            else if(A[mid]=target)
					left=mid+1;			//在右半边
                else
					right=mid-1;		//在左半边
            }
			else
			{
                if(A[left]<=target && A[mid]>target)
					right=mid-1;		//在左半边
                else 
					left=mid+1;			//在右半边
            }
        }
        return -1;
    }
};

int main(void)
{
	int A[]={4,5,6,7,0,1,2};
	int n=sizeof(A)/sizeof(A[0]);
	int target=0;
	cin>>target;
	class Solution object;
	int index=object.search(A,n,target);
	cout<