Rock

static int binSearch(int[] a, int target) {
	    // keep track of search space
		int b= 0;
		int e= a.length;

		while (b <= e) {
			int mid = (b + e)/2;

			if (a[mid] == target) return mid;
			if (a[mid] < target) b = mid + 1;
			else e = mid - 1;
		}
		//if failed
		return -1;
	  }