IOUtil.java

import java.io.*;

public class IOUtil {

  private static StreamTokenizer tokenizer = new StreamTokenizer(
      new InputStreamReader(System.in));

  public static double readDouble() {

    tokenizer.resetSyntax();
    tokenizer.whitespaceChars(0, ' ');
    tokenizer.wordChars(33, 255);

    try {
      if (tokenizer.nextToken() == StreamTokenizer.TT_EOF) {
        throw new IOException("End Of File found.");
      } else {
        return Double.parseDouble(tokenizer.sval);
      }
    } catch (NumberFormatException nfe) {
      return readDouble();
    } catch (java.io.IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static float readFloat() {

    tokenizer.resetSyntax();
    tokenizer.whitespaceChars(0, ' ');
    tokenizer.wordChars(33, 255);

    try {
      if (tokenizer.nextToken() == StreamTokenizer.TT_EOF) {
        throw new IOException("End Of File found.");
      } else {
        return Float.parseFloat(tokenizer.sval);
      }
    } catch (NumberFormatException nfe) {
      return readFloat();
    } catch (java.io.IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static int readInt() {

    try {

      tokenizer.resetSyntax();
      tokenizer.whitespaceChars(0, ' ');
      tokenizer.wordChars(33, 255);

      if (tokenizer.nextToken() == StreamTokenizer.TT_EOF) {
        throw new IOException("End Of File found.");
      } else {
        return (int) Double.parseDouble(tokenizer.sval);
      }
    } catch (NumberFormatException nfe) {
      return readInt();
    } catch (java.io.IOException e) {
      throw new RuntimeException(e);
    }
  }

  public static String readString() {
    try {
      tokenizer.resetSyntax();
      tokenizer.whitespaceChars(0, ' ');
      tokenizer.wordChars(33, 255);

      if (tokenizer.nextToken() == StreamTokenizer.TT_EOF) {
        throw new IOException("End Of File found.");
  
    } else {
        return tokenizer.sval;
      }
    } catch (java.io.IOException e) {
      throw new RuntimeException(e);
    }

  }
  
  public static String readLine() {
    try {
        InputStreamReader converter = new InputStreamReader(System.in);
        BufferedReader in = new BufferedReader(converter);
        return(in.readLine());
    } catch (IOException e) {
        return null;
    }
  } 

}