1930: a+b=100

内存限制:128 MB 时间限制:1.000 S
评测方式:文本比较 命题人:
提交:3 解决:1

题目描述

given a unordered interger list,find how many pairs of numbers whose sum is 100.

for example,-1 0 50 70 101 88 120,just one pair(-1 and 101)  

输入

many cases,for each case,input n to denote the number of the list,if n is 0,the input ends,and then input n non-repeating integers 

输出

the number of pairs meeting the demand

样例输入 复制

10
100 20 30 45 46 60 70 80 90 10
7
120 -1 0 50 70 88 101
0

样例输出 复制

3
1