对有重复数组的情况也有效

public class Solution {    public boolean search(int[] A, int target) {	     int left = 0, right = A.length - 1;	     while( left <= right){	    	 int mid = (left + right)/2;	    	 if(A[mid] == target) return true;	    	 if(A[left] < A[mid]){	    		 if(target <= A[mid] && target >= A[left])	    			 right = mid - 1;	    		 else left = mid + 1;	    	 } else if (A[left] > A[mid]){	    		 if(target >= A[left] || target <= A[mid])	    			 right = mid -1;	    		 else left = mid + 1;	    	 }	    	 else left ++;	     }	     return false;	    }}