While submitting solutions to Online Judges like CC, CF, or any other coding competitions online like Facebook Hacker Cup, Google Code Jam, should I put the following code in comments or leave it as it is in C++?
#ifndef ONLINE_JUDGE
freopen("input.txt", "r", stdin);
freopen("output.txt", "w", stdout);
#endif
Also in Java, if use FileReader and PrintWriter to read and write from external files, and to print should I change
BufferedReader br = new BufferedReader( new FileReader("input.txt"));
PrintWriter pw=new PrintWriter(new BufferedWriter(new FileWriter("output.txt")));
to
BufferedReader br = new BufferedReader( new InputStreamReader(System.in));
and also change pw.wrtie() to System.out.print() ?