有15个数已按由大到小的顺序存放在一个数组中，现再输入一个数，要求用折半查找法找出该数是数组中第几个元素的值。如果该数不在数组中，则打印出“无此数”*/-There are 15 numbers in ascending order has been placed in an array, now and then enter a number, asked to use a binary search method to find the number of elements in the array in the first few values. If this number is not in the array, then print out the "no such number"* /