Question

JAVA

Your task is to implement a simple pattern-matching method. The method is supplied a pattern to find (the “needle”) and a text to search (the “haystack”). The pattern will be a sequence of characters and, optionally, one or more dashes (-). A dash represents a wildcard, which matches any character. The method needs to return an array of all substrings of the haystack that matches the needle pattern – all characters are the same, or the pattern character is a dash. For example…

patternMatch("A--G-", "ACTGGTACTGA") -> ["ACTGG", "ACTGA"]

patternMatch("-GG-", "ACTGGTACTGA") -> ["TGGT"]

patternMatch("-GGC", "ACTGGTACTGA") -> []

For this problem you are NOT allowed to employ substring or pattern-matching methods – it must be implemented via looping over characters in the needle/haystack strings. You may create temporary methods/programs for your own debugging, but there is no main to complete/submit.

Answer 1

thanks for the question, here is the Java code with screenshot.

Just submit the method only for your assignment

====================================================================================

import java.util.ArrayList;
import java.util.Arrays;

public class PatternMatching {

    public static String[] patternMatch(String pattern, String text) {

        ArrayList<String> patterns = new ArrayList<>();
        int index = 1;
        for (int i = 0; i <= text.length() - pattern.length(); i++) {

            String subText = text.substring(i, i + pattern.length());
            boolean match = true;
            for (int j = 0; j < pattern.length(); j++) {
                if (subText.charAt(j) == pattern.charAt(j) || pattern.charAt(j) == '-'
                 ) {
                    continue;
                } else {
                    match = false;
                    break;
                }
            }
            if(match){
                patterns.add(subText);
            }


        }

        String [] matches = new String[patterns.size()];
        for(int pos=0;pos<patterns.size();pos++){
            matches[pos]=patterns.get(pos);
        }
        return matches;

    }

    public static void main(String[] args) {

        String[] matches = patternMatch("A--G-", "ACTGGTACTGA");
        System.out.println(Arrays.toString(matches));
         matches = patternMatch("-GG-", "ACTGGTACTGA");
        System.out.println(Arrays.toString(matches));
        matches = patternMatch("-GGC", "ACTGGTACTGA");
        System.out.println(Arrays.toString(matches));

    }
}

======================================================================================

import public class PatternMatching public static Stringtl patternMatch (String pattern, String text) 39 E public static void main (String[] args) 1 ) 40 50 51 PatternMatching main PatternMatching "C:Program Files\Java jdk-11\binljava.exe"-javaagent:C:\Program FilesJetBrains\Inte ACTGG, ACTGA] TGGT Process finished with exit code 0 r--I

import public class PatternMatching public static Stringtl patternMatch (String pattern, String text) 39 E public static void main (String[] args) 1 ) 40 50 51 PatternMatching main PatternMatching "C:Program Files\Java jdk-11\binljava.exe"-javaagent:C:\Program FilesJetBrains\Inte ACTGG, ACTGA] TGGT Process finished with exit code 0 r--I