移位有序數組的尋找

一個數組是由一個遞減數列左移若干位形成的，比如{4，3，2，1，6，5} 
是由{6，5，4，3，2，1}左移兩位形成的，在這種數組中尋找某一個數。 

public class Test {//遞減序列的二分public static int binarySearch(int[] array,int begin,int end,int goal){int mid = (begin + end)/2;while(begin <= end){if(array[mid] == goal){return mid;}else if(array[mid] < goal){return binarySearch(array,begin,mid-1,goal);}else{return binarySearch(array,mid+1,end,goal);}}return -1;}//找到2個遞減序列的分界線  傳回值是第二個遞減序列開始位置public static int get(int[] array){int i = array.length - 1;while(i >= 0){if(array[i] <= array[i-1]){i--;}else{return i;}}return -1;}public static void main(String[] args) {// TODO Auto-generated method stubint[] a = {7,6,5,4,3,2,1,9,8};int goal = 8;int i = get(a);if(goal >= a[i-1] && goal < a[0]){System.out.print(binarySearch(a, 0, i-1, goal));}else{System.out.print(binarySearch(a, i, a.length-1, goal));}}}