hdu 4493 卡输入输出

题目地址： http://acm.hdu.edu.cn/showproblem.php?pid=4493

一个double 如果就用cout 貌似会用科学技术法；

#include<iostream>

using namespace std;

int x1(double k)
{
   k*=10;
   return (int)k%10;


}

int x2(double k)
{
   k*=100;
   return (int)k%10;

}
int x3(double k)
{
   k*=1000;
   return (int)k%10;

}


int main()
{
   int T;
   cin>>T;
   while(T--)
    {
       double ans=0;
       for(int i=0;i<12;i++)
         {
             double temp;
             cin>>temp;
             ans+=temp;

         }
        ans/=12;

      if(x3(ans)>=5)  ans+=0.01;

      cout<<"$"<<(long long )ans;
      int a1=x1(ans);

      int a2=x2(ans);

       if(a1==0&&a2==0)   cout<<endl;
      else if(a1!=0&&a2==0)  cout<<"."<<a1<<endl;
      else cout<<"."<<a1<<a2<<endl;

   //   cout<<"$"<<ans<<endl;
   //这样就会错
    }
}