zoj 1760 Doubles

#include "iostream"
#include "set"
using namespace std;

int main()
{
set<int> s;
set<int>::iterator it;
int temp;
while (cin >> temp && temp != -1)
{
if (temp != 0)
s.insert(temp);//放进容器中进行自动排序！
else
{
int count = 0;
for (it = s.begin(); it != s.end(); it++)
if (s.find((*it) * 2) != s.end())//在容器中查找是否存在！
count++;
cout << count << endl;
s.clear();
}
}
}