package io;

import java.lang.*;
import java.io.* ;


/** for flexible reading of InputStream; all methods are static.
    Works fine but does not handle re-positioning of the pointer after
    reading past the end-of-word the terminating non-letterOrDigit character;

    All methods come in three versions: 1) meth(InputStream ip) for reading
    from ip; 2) meth() for reading from terminal; 3) askMeth(String s) for
    reading from terminal with a prompt s; */

public class les {
  private static char EOF= ((char)(-1));

    /** returns next character */
  public static final char tegn(InputStream in) {
    char c='0'; int ch=0; 
    try{ ch= in.read(); c= (char)ch; }
    catch(IOException e){}
    return c;
  }

    /** returns next character distinct from space ' '*/
  public static final char tegnNB(InputStream in) {
    char c='0'; int ch=0; 
    try{ ch= in.read(); c= (char)ch; 
    while (c==' ') {ch= in.read(); c=(char)ch;}
    }
    catch(IOException e){}
    return c;
  }

    /** returns next non-formatting character 
	(distinct from space, \n, \r, \t) */
    public static char tegnNF(InputStream in) {
	char c=' ';
	try{ c= (char)in.read();
	while (c!=EOF && (c==' ' || c=='\n' || c=='\r' || c=='\t')) c= (char)in.read();
	} catch(IOException e){}
	return c;
    }

    /** returns next integer - skips possible initial non-digit characters; 
	reads one character past the last digit !!! */
  public static final int htall(InputStream in) {
    int r=0, ch, s=0;
    try{ 
      ch= in.read()-48; 
      while (ch<0 || ch>9) {s=ch; ch= in.read()-48;}
      r= ch;
      ch= in.read()-48;
      while (ch >= 0 && ch <= 9) {r= (r*10)+ch; ch= in.read()-48; }
    }   catch(IOException e){}
    s= s+48;
    if ((char)s == '-') {r= -r;}
    return r;
  }     

    /** returns boolean - false iff next NB character is 'n', 'N', '0' or '-' */
  public static final boolean bool(InputStream in) {
      char c= tegnNB(in); 
      if ( c=='n' || c=='N' || c=='0' || c=='-') return false;
      else return true;
  }

    /** reads next word - non-SPACE characters between SPACEs; 
	skips initial SPACEs */
  public static final String ord(InputStream in) {
      char c= tegn(in); String s= new String("");
      while (c==' ') { c= tegn(in); }
      while (c != ' ') {s= s+c; c= tegn(in);}
      return s;
  }

    /** read word starting with a letter and containing only letters or digits;
	skips initial non-letters;
	reads one extra character past the last letter/digit !!! */
  public static final String ordLD(InputStream in) {
      int ch, i; char c;
      String s= new String("");
      try{
	  ch= in.read(); c= (char)ch; i=1;
	  while (!Character.isLetter(c)) { ch= in.read(); c=(char)ch; i= i+1;} 
	  while (Character.isLetterOrDigit(c)) {s=s+c; ch= in.read();c=(char)ch;i=i+1;}
      }
      catch(IOException e){System.out.println("smth. wrong !!!");}
      return s;
  }


  /* above methods but now for reading from the terminal */


    /** as 'htall(InputStream in)' but reads from terminal */
  public static final int htall()    { return htall(System.in); }

    /** as 'tegn(InputStream in)' but reads from terminal */
  public static final char tegn()    { return tegn(System.in); }

    /** as 'tegnNB(InputStream in)' but reads from terminal */
  public static final char tegnNB()  { return tegnNB(System.in); }

    /** as 'tegnNF(InputStream in)' but reads from terminal */
  public static final char tegnNF()  { return tegnNF(System.in); }

    /** as 'bool(InputStream in)' but reads from terminal */
  public static final boolean bool() { return bool(System.in); }

    /** as 'ord(InputStream in)' but reads from terminal */
  public static final String ord()   { return ord(System.in); }

    /** as 'ordLD(InputStream in)' but reads from terminal - works fine*/
  public static final String ordLD() { return ordLD(System.in); }


  /* above methods for reading from the terminal with an 'ask for' prompt */


    /** as 'htall()' but with a prompt */
  public static final int askHtall(String s) {
      System.out.print(s+": "); return htall(System.in); 
  }

    /** as 'bool()' but with a prompt */
  public static final boolean askBool(String s) {
      System.out.print(s+": "); return bool(System.in); 
  }

    /** as 'ord()' but with a prompt */
  public static final String askOrd(String s) {
      System.out.print(s+": "); return ord(System.in); 
  }

    /** as 'ordLD()' but with a prompt */
  public static final String askOrdLD(String s) {
      System.out.print(s+": "); return ordLD(System.in); 
  }

    /** as 'tegn()' but with a prompt */
  public static final char askTegn(String s) {
      System.out.print(s+": "); return tegn(System.in); 
  }

    /** as 'tegnNB()' but with a prompt */
  public static final char askTegnNB(String s) {
      System.out.print(s+": "); return tegnNB(System.in); 
  }

    /** as 'tegnNF()' but with a prompt */
  public static final char askTegnNF(String s) {
      System.out.print(s+": "); return tegnNF(System.in); 
  }
}