I have recently started programming,please help me. where is wrong in this program?
It was compilition error.
#include<iostream>
#include<math>
double b[500000];
int main(int argc, char* argv[])
{  unsigned long long a,i=0,j;
    while(a!=EOF) {std::cin>>a;
    i++; b[i]=sqrt(a); }
         for(j=i;j>1;j--)
         std::cout<<b[j];
        return 0;
}