fork(1) download
copy 
  1. import java.util.concurrent.TimeUnit;
  2. import java.util.regex.Pattern;
  3. import static java.lang.System.*;
  4. import static java.util.concurrent.TimeUnit.NANOSECONDS;
  5.  
  6.  
  7. public class Main
  8. {
  9.    public static void main(String[] args)
  10.     {
  11.         long ns = 0L;
  12.         Pattern lazy   = Pattern.compile("^(11+?)\\1+$");
  13.         Pattern greedy = Pattern.compile("^(11+)\\1+$" );
  14.         ns=nanoTime();  lazy  .matcher(new Rep('1',100160079)).matches(); out.println("Lazy Rep    : "+ NANOSECONDS.toMillis(nanoTime()-ns));
  15.         //ns=nanoTime();  greedy.matcher(new Rep('1',100160079)).matches();out.println("Greedy Rep  :"+ NANOSECONDS.toMillis(nanoTime()-ns));
  16.  
  17. 		//ns=nanoTime(); "1".repeat( 100160079 ).matches("^(11+?)\\1+$") ; out.println("Lazy String:"+ NANOSECONDS.toMillis(nanoTime()-ns));
  18. 		//ns=nanoTime(); "1".repeat( 100160079 ).matches("^(11+)\\1+$") ; out.println("Greedy String:"+ NANOSECONDS.toMillis(nanoTime()-ns));        
  19.  
  20.         //no Pattern.compile()
  21.         ns=nanoTime(); lazy.matcher("1".repeat( 100160079 )).matches(); out.println("Lazy String : "+ NANOSECONDS.toMillis(nanoTime()-ns));
  22.         //ns=nanoTime(); greedy.matcher("1".repeat( 100160079 )).matches(); out.println("Greedy String:"+ NANOSECONDS.toMillis(nanoTime()-ns));
  23.  
  24.     }
  25.  
  26.  
  27.  
  28.  
  29. static class Rep implements CharSequence
  30. {
  31.     String str = null;
  32.     int    len;
  33.     char  base;
  34.  
  35.     public Rep(char x, int count)
  36.     {
  37.         this.len  = count;
  38.         this.base = x;
  39.     }
  40.  
  41.     @Override
  42.     public int length()
  43.     {
  44.         return len;
  45.     }
  46.  
  47.     @Override
  48.     public char charAt(int index)
  49.     {
  50.         return base;
  51.     }
  52.  
  53.     @Override
  54.     public CharSequence subSequence(int beginIndex, int endIndex)
  55.     {
  56.         if (beginIndex < 0) {
  57.             throw new StringIndexOutOfBoundsException(beginIndex);
  58.         }
  59.         if (endIndex > this.len) {
  60.             throw new StringIndexOutOfBoundsException(endIndex);
  61.         }
  62.         int subLen = endIndex - beginIndex;
  63.         if (subLen < 0) {
  64.             throw new StringIndexOutOfBoundsException(subLen);
  65.         }
  66.         return ((beginIndex == 0) && (endIndex == this.len)) ? this
  67.                 : new Rep(this.base, subLen);
  68.     }
  69.  
  70.     @Override
  71.     public String toString()
  72.     {
  73.         return null!=str ?  str : (this.str  = new String(new char[]{base}).repeat(len));
  74.     }
  75.  
  76.  
  77. }
  78. }
  79.  
Success #stdin #stdout 1.4s 136232KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
Lazy Rep    : 195
Lazy String : 1112
https://ideone.com/8eYFU7
language:
Java (HotSpot 12)
created:
3 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!