#!/usr/imports/bin/perl
use English;

# Change this value to select which solution to run
$choice = 1;


if ($choice == 1) {
  #ex_02-1
  #Learning Perl Appendix A, Exercise 2.1
  $pi = 3.141592654;
  $result = 2 * $pi * 12.5;
  print "radius 12.5 is circumference $result\n";
  
}


if ($choice == 2) {
  #ex_02-2
  #Learning Perl Appendix A, Exercise 2.2
  print "What is the radius: ";
  chomp($radius = <STDIN>);
  $pi = 3.141592654;
  $result = 2 * $pi * $radius;
  print "radius $radius is circumference $result\n";
  
}


if ($choice == 3) {
  #ex_02-3
  #Learning Perl Appendix A, Exercise 2.3
  print "First number: "; chomp($a = <STDIN>);
  print "Second number: "; chomp($b = <STDIN>);
  $c = $a * $b; print "Answer is $c.\n";
  
}


if ($choice == 4) {
  #ex_02-4
  #Learning Perl Appendix A, Exercise 2.4
  print "String: "; $a = <STDIN>;
  print "Number of times: "; chomp($b = <STDIN>);
  $c = $a x $b; print "The result is:\n$c";
  
}


if ($choice == 5) {
  #ex_03-3
  #Learning Perl Appendix A, Exercise 3.3
  srand;
  print "Enter list of strings (end with control-D): "; 
  @b = <STDIN>;
  $random_index = rand(@b);
  print "Answer: $b[$random_index]\n";
  
  
}


if ($choice == 6) {
  #ex_03-3
  #Learning Perl Appendix A, Exercise 3.3, alternative solution
  srand;
  print "Enter list of strings (end with control-D): "; 
  while ($line = <STDIN>) {
   chomp($line);
   push @b, $line;
  }
  $random_index = rand(@b);
  print "Answer: $b[$random_index]\n";
  
  
}


if ($choice == 7) {
  #ex_04-2
  #Learning Perl Appendix A, Exercise 4.2
  print "What temperature is it? ";
  chomp($temperature = <STDIN>);
  if ($temperature > 75) {
      print "Too hot!\n";
  } elsif ($temperature < 68) {
      print "Too cold!\n";
  } else {
      print "Just right!\n";
  }
  
}


if ($choice == 8) {
  #ex_04-3
  #Learning Perl Appendix A, Exercise 4.3
  print "Enter a number (999 to quit): ";
  chomp($n = <STDIN>);
  while ($n != 999) {
      $sum += $n;  # Could also do: $sum = $sum + $n;
      print "Enter another number (999 to quit): ";
      chomp($n = <STDIN>);
  }
  print "the sum is $sum\n";
}