Search in Rotated Sorted Array II

如果有重复数字，那么，如果A[m]>=A[l],那么[l,m]为递增序列的假设就不能成立了，比如如下数据
[1,3,1,1,1]

解决办法：
如果A[m]>=A[l]不能确定递增，那就把它拆分成两个条件
1. A[m]>A[l]  递增
2. A[m] ==A[l] 确定不了，那就l++，往下看一步即可。

 bool search(int A[], int n, int target) {  
            int start = 0;  
            int end = n-1;  
            while(start <= end)  
            {  
                 int mid = (start+end)/2;  
                 if(A[mid] == target) return true;  
                 if(A[start] < A[mid])  
                 {  
                      if(target>=A[start] && target<A[mid])  
                           end = mid-1;  
                     else   
                          start = mid+1;  
                 }  
                 else if(A[start] > A[mid])  
                 {  
                      if(target>A[mid] && target<=A[end])  
                           start = mid+1;  
                      else  
                           end = mid-1;  
                 }  
                else //skip duplicate one, A[start] == A[mid]  
                      start++;  
            }  
            return false;  
       }