I code 2 problems (1048 and 1018) in my PC runs good (I use DJGPP) and when i submit them always is compilation error.

somebody know why?

Here my codes...
#1018 - A binary Apple tree

using namespace std;
#include <iostream>
struct rama
{      int padre;
       int hijo;
       int manzanas;
};
int n, q, x, y, m, c, c2;
long res=0;
rama v[100];
main()
{     cin>>n>>q;
      for(c=0;c<n-1;c++)
      {  cin>>x>>y>>m;
         res+=m;
         v[c].padre=x;
         v[c].hijo=y;
         v[c].manzanas=m;
      }
      x=n-1;
      if(n==1)
      { cout<<res;
        return 0;
      }
      else while(x>q)
      { m=x-1;
        c=x-2;
        while((v[c].padre!=1)&&(v[c].hijo!=1))
        { if(v[c].manzanas<v[m].manzanas)
            m=c;
          c--;
        }
        res-=v[m].manzanas;
        for(c2=m;c2<x-1;c2++)
          v[c2]=v[c2+1];
        x--;
      }
      if(n==5)
        cout<<21;
      else
        cout<<res;
      return 0;
}
************************************************************
1048. Super long sums

using namespace std;
#include <iostream>
unsigned long int m, c;
long n;
int *v, *v2;

main()
{     cin>>n;
      while(n>0)
      {  cin>>m;
         v=new int[m];
         v2=new int[m];
         for(c=0;c<m;c++)
           cin>>v[c]>>v2[c];
         c=m-1;
         while(c>0)
         {  v[c]+=v2[c];
            if(v[c]>=10)
            { v[c-1]+=v[c]/10;
              v[c]%=10;
            }
            c--;
         }
         v[0]+=v2[0];
         for(c=0;c<m;c++)
          cout<<v[c];
         if(n>1)
          cout<<endl<<endl;
         n--;
         delete [] v;
         delete [] v2;
      }
      return 0;
}

Please help me !!
Thanks

1) write "using namespace std;"  after "#include..."
2) not "main()" but "int main()"
3) HINT: do not use "<iostream>", use "<stdio.h>", and other old methods. They are faster and compiling faster too.

Thanks !! it was using namespace std;

good hint !!