有15个数按由小到大顺序放在一个数组中，输入一个数，要求用折半查找法找出该数是数组中的第几个元素的值，如果该数不在数组中，则打印出无此数-15 the number of small to large order placed by an array, enter a few, require half the number of search method is to identify the array elements in the first few values, if the number is not an array, then print out not the number of