Drop duplicated sample code (#2389) [ci skip]

* Drop duplicated sample code

* Drop another style sample

https://github.com/ruby/ruby/pull/2389#issuecomment-522489520

* Update sample list

sample/README

@@ -16,7 +16,6 @@ fib.pl		Fibonacci number (Perl)
 fib.py		Fibonacci number (Python)
 fib.rb		Fibonacci number (Ruby)
 fib.scm		Fibonacci number (Scheme)
-freq.rb		count word occurrence
 from.rb		scan mail spool
 fullpath.rb	convert ls -lR to fullpath format
 less.rb		front end for less
@@ -29,7 +28,6 @@ mpart.rb	split file int multi part
 observ.rb	observer design pattern sample
 occur.pl	count word occurrence (Perl)
 occur.rb	count word occurrence (Ruby)
-occur2.rb	count word occurrence - another style
 philos.rb	famous dining philosophers
 pi.rb		calculate PI
 rcs.awk		random character stereogram (AWK)

sample/freq.rb

@@ -1,12 +0,0 @@
-# word occurrence listing
-# usage: ruby freq.rb file..
-freq = Hash.new(0)
-while line = gets()
-  line.scan(/\w+/) do |word|
-    freq[word] += 1
-  end
-end
-
-for word in freq.keys.sort!
-  print word, " -- ", freq[word], "\n"
-end

sample/occur.rb

@@ -2,7 +2,7 @@
 # usage: ruby occur.rb file..
 freq = Hash.new(0)
 while line = gets()
-  for word in line.split(/\W+/)
+  line.scan(/\w+/) do |word|
     freq[word] += 1
   end
 end

sample/occur2.rb

@@ -1,13 +0,0 @@
-# word occurrence listing
-# usage: ruby occur2.rb file..
-freq = {}
-ARGF.each_line do |line|
-  for word in line.split(/\W+/)
-    freq[word] ||= 0
-    freq[word] += 1
-  end
-end
-
-for word in freq.keys.sort
-  printf("%s -- %d\n", word, freq[word])
-end