Tutorial Addendum on Perl - Allotment A - Cord Achievement

This affiliate describes:

    

    
• How the two alotof accepted cord functions accomplish beneath altered environments.
  
      



    
• A Perl program to analysis the achievement of substr() and index().
  
      



    
• A Java program to analysis the achievement of substring() and indexOf().
  
      



    

Perl Analysis Program - SubstringTest.pl

    

I wrote the afterward program, SubstringTest.pl, in 1996 on a SunOS arrangement to analysis

    

the achievement of substr() and index() functions:

    

 

    
#- SubstringTest.pl

    
#- Absorb (c) 1996 by Dr.  Yang

    
#

    
   ($numChar, $numTest) = @ARGV;

    
   $numChar = 10 unless $numChar;

    
   $numTest = 1 unless $numTest;

    
   $baseString = &setString($numChar);

    
   $subString = &setString($numChar);

    
   $startTime = time();

    
   $numMatch = 0;

    
   for ($i=0; $i<$numTest; $i++) {

    
      $numMatch = &test();

    
   }

    
   $endTime = time();

    
   $totalTime = $startTime - $endTime;

    
   $averageTime = $totalTime/$numTest;

    
   print("Number of tests = $numTest

");

    
   print("Number of characters = $numChar

");

    
   print("Number of matches = $numMatch

");

    
   print("Total time = $totalTime seconds

");

    
   print("Average time = $averageTime seconds

");

    
   exit;

    
sub setString {

    
   local($size) = @_;

    
   bounded $str = "";

    
   local($i,$n,$c);

    
   for ($i=0; $i<$size; $i++) {

    
      $n = int(rand(96)) + 32;

    
      $c = chr($n);

    
      $str .= $c;

    
   }

    
   acknowledgment $str;

    
}

    
sub analysis {

    
   local($i,$j,$l);

    
   bounded $str = "";

    
   bounded $num = 0;

    
   bounded $pos = -1;

    
   for ($i=0; $i<$numChar; $i++) {

    
      $l = $i+1;

    
      for ($j=0; $j<$numChar-$i; $j++) {

    
         $str = substr($subString,$j,$l);

    
         $pos = index($baseString,$str);

    
         $num++ if ($pos<0);

    
      }

    
   }

    
   acknowledgment $num;

    
}

    

The abstraction is to get two strings of the aforementioned breadth ramdonly, yield all accessible substrings

    

out of the first one, and try to bout them in the additional one with index().

    

Running this program with ActivPerl v5.6.1 on Windows 2000 arrangement gave me:

    

 

    
>SubstringTest.pl 50 1000

    
Number of tests = 1000

    
Number of characters = 50

    
Number of matches = 1257

    
Total time = 8 seconds

    
Average time = 0.008 seconds

    
>SubstringTest.pl 100 1000

    
Number of tests = 1000

    
Number of characters = 100

    
Number of matches = 4976

    
Total time = 31 seconds

    
Average time = 0.031 seconds

    
>SubstringTest.pl 200 1000

    
Number of tests = 1000

    
Number of characters = 200

    
Number of matches = 19916

    
Total time = 137 seconds

    
Average time = 0.137 seconds