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45 lines
1.1 KiB
Java
45 lines
1.1 KiB
Java
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import edu.princeton.cs.introcs.StdIn;
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import edu.princeton.cs.introcs.StdOut;
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/*************************************************************************
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* Compilation: javac GREP.java
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* Execution: java GREP regexp < input.txt
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* Dependencies: NFA.java
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* Data files: http://algs4.cs.princeton.edu/54regexp/tinyL.txt
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*
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* This program takes an RE as a command-line argument and prints
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* the lines from standard input having some substring that
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* is in the language described by the RE.
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*
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* % more tinyL.txt
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* AC
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* AD
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* AAA
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* ABD
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* ADD
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* BCD
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* ABCCBD
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* BABAAA
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* BABBAAA
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*
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* % java GREP "(A*B|AC)D" < tinyL.txt
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* ABD
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* ABCCBD
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*
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*************************************************************************/
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public class GREP {
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public static void main(String[] args) {
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String regexp = "(.*" + args[0] + ".*)";
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NFA nfa = new NFA(regexp);
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while (StdIn.hasNextLine()) {
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String txt = StdIn.readLine();
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if (nfa.recognizes(txt)) {
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StdOut.println(txt);
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}
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}
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}
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}
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