/in/foo.cc: In function 'int main()':
/in/foo.cc:16:14: error: 'n' was not declared in this scope
  scanf("%d",&n);
              ^
/in/foo.cc:17:6: error: 'i' was not declared in this scope
  for(i=1;i<=n;i++)
      ^
/in/foo.cc:22:22: error: 'memcpy' was not declared in this scope
  memcpy(b,a,sizeof(a));
                      ^
/in/foo.cc:23:20: error: 'sort' was not declared in this scope
  sort(a+1,a+1+n,cmp);
                    ^
/in/foo.cc:24:6: error: 'i' was not declared in this scope
  for(i=1;i<=n;i++)
      ^
/in/foo.cc:28:6: error: 'i' was not declared in this scope
  for(i=1;i<=n;i++)
      ^
/in/foo.cc:29:3: error: 'ans' was not declared in this scope
   ans+=b[i];
   ^~~
/in/foo.cc:30:16: error: 'ans' was not declared in this scope
  printf("%d\n",ans);
                ^~~