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  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.         var s="1".repeat( 100160079 );
  22.         ns=nanoTime(); lazy.matcher(s).matches(); out.println("Lazy String : "+ NANOSECONDS.toMillis(nanoTime()-ns));
  23.         //ns=nanoTime(); greedy.matcher("1".repeat( 100160079 )).matches(); out.println("Greedy String:"+ NANOSECONDS.toMillis(nanoTime()-ns));
  24.  
  25.     }
  26.  
  27.  
  28.  
  29.  
  30. static class Rep implements CharSequence
  31. {
  32.     String str = null;
  33.     int    len;
  34.     char  base;
  35.  
  36.     public Rep(char x, int count)
  37.     {
  38.         this.len  = count;
  39.         this.base = x;
  40.     }
  41.  
  42.     @Override
  43.     public int length()
  44.     {
  45.         return len;
  46.     }
  47.  
  48.     @Override
  49.     public char charAt(int index)
  50.     {
  51.         return base;
  52.     }
  53.  
  54.     @Override
  55.     public CharSequence subSequence(int beginIndex, int endIndex)
  56.     {
  57.         if (beginIndex < 0) {
  58.             throw new StringIndexOutOfBoundsException(beginIndex);
  59.         }
  60.         if (endIndex > this.len) {
  61.             throw new StringIndexOutOfBoundsException(endIndex);
  62.         }
  63.         int subLen = endIndex - beginIndex;
  64.         if (subLen < 0) {
  65.             throw new StringIndexOutOfBoundsException(subLen);
  66.         }
  67.         return ((beginIndex == 0) && (endIndex == this.len)) ? this
  68.                 : new Rep(this.base, subLen);
  69.     }
  70.  
  71.     @Override
  72.     public String toString()
  73.     {
  74.         return null!=str ?  str : (this.str  = new String(new char[]{base}).repeat(len));
  75.     }
  76.  
  77.  
  78. }
  79. }
  80.  
Success #stdin #stdout 1.45s 136148KB
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stdin
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Standard input is empty
stdout
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Lazy Rep    : 209
Lazy String : 1092
https://ideone.com/M6ZXhR
language:
Java (HotSpot 12)
created:
3 years ago
visibility:
public

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