tri:Pls help for this programing problem in c++ (standard IO without file read/write),better with some comment about why coding that way,thanks

Problem C: Triangle Time limit:3 seconds Problem Description different triangles that can form by these segments. Input File Format There are several test case. The first line of each case is the number of segments and the second line contains n positive integers which are the lengths of these segments. You may assume that n is no more than 30 and the segment lengths are no more than 10000. The case of n-0 indicates the end of input. Output Format For each test case, output the number of different triangles in one line. Example Sample Input: Sample Output: 24635 0