Search in Rotated Sorted Array
    描述：
Suppose a sorted array is rotated at some pivot unknown to you beforehand.
2.1 数组 5
(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.

解答：

#include<iostream>
using namespace std;
int search(int A[],int n,int target);
void main()
{   int A[7]={4,5,6,7,0,1,2};cout<<"the answer is"<<search(A,7,6)<<endl;
}
int search(int A[],int n,int target)
{int first=0,last=n;while(first!=last){const int mid=(first+last)/2;if(A[mid]==target) return target;if(A[first]<=A[mid]){if(A[first]<=target&&target<=A[mid]){last=mid;}else first=mid+1;}else{if(A[mid]<=target&&target<=A[last]){first=mid+1;}else last=mid;}}return -1;
}