Find the number from descending order array with left rotate N element

Find one number from descending order array

5 /**
  6  * @func: the binary search fur descending order array.
  7  */
  8 int binary_search(int arr[], int left, int right, int val){
  9     int ret = -1;
 10     if (NULL == arr || left >= right)
 11         return ret;
 12
 13     while(left <= right){
 14         int middle = (left & right) + ((left ^ right) >> 1);
 15         if (val == arr[middle]){
 16             ret = middle;
 17             break;
 18         }else if (arr[middle] > val){
 19             left = middle + 1;
 20         }else {
 21             right = middle - 1;
 22         }
 23     }
 24     return ret;
 25 }
 26
 27 /**
 28  * @func: find the number from descending order array with left rotate N element.
 29  * @param {int} val, the number should be found
 30  * @param {array} arr, the array with different numbers and which the number should be found.
 31  * @param {int} left, the left boundary of the array.
 32  * @param {int} right, the right boundary of the array.
 33  * @return {int}, the index of number in this array.
 34  *                -1 indicates this number cannot be found in the array.
 35  */
 36 int find_from_orderarray(int val, int arr[], int left, int right){
 37     int ret = -1;
 38     if (NULL == arr || left >= right)
 39         return ret;
 40
 41     int middle = (left & right) + ((left ^ right) >> 1);
 42     if (val == arr[middle]){
 43         return middle;
 44     }
 45     if (val == arr[left]){
 46         return left;
 47     }
 48     if (val == arr[right]){
 49         return right;
 50     }
 51
 52     if (arr[left] > arr[middle]){
 53         if( val > arr[middle] && val < arr[left]){
 54             // It is descending order array from left to middle, find val by binary search.
 55             ret = binary_search(arr, left, middle, val);
56         } else {
 57             // Just like another same array from middle to right.
 58             ret = find_from_orderarray(val, arr, middle, right);
 59         }
 60     }else {
 61         if ( val < arr[middle] && val > arr[right]){
 62             ret = binary_search(arr, middle, right, val);
 63         } else {
 64             ret = find_from_orderarray(val, arr, left, middle);
 65         }
 66     }
 67     return ret;
 68 }
 69
 70 int main(){
 71     int array[] = {4, 3, 2, 1, 10, 9, 8, 7, 6, 5};
 72     cout << "the 2 are in the " << find_from_orderarray(2, array, 0, sizeof(array)/sizeof(array[0]) - 1) << endl;
 73     return 0;
 74 }