Rep-string: Difference between revisions

Alternative version avoiding the use of 'goto'

<syntaxhighlight lang="java">

import java.util.ArrayList;

import java.util.List;

public final class RepStrings {

public static void main(String[] aArgs) {

List<String> tests = List.of( "1001110011", "1110111011", "0010010010",

"1010101010", "1111111111", "0100101101", "0100100", "101", "11", "00", "1" );

System.out.println("The longest rep-strings are:");

for ( String test : tests ) {

List<String> repeats = repString(test);

String result = repeats.isEmpty() ? "Not a rep-string" : repeats.get(repeats.size() - 1);

System.out.println(String.format("%10s%s%s", test, " -> ", result));

}

}

private static List<String> repString(String aText) {

List<String> repetitions = new ArrayList<String>();

for ( int length = 1; length <= aText.length() / 2; length++ ) {

String possible = aText.substring(0, length);

int quotient = aText.length() / length;

int remainder = aText.length() % length;

String candidate = possible.repeat(quotient) + possible.substring(0, remainder);

if ( candidate.equals(aText) ) {

repetitions.add(possible);

}

}

return repetitions;

}

}

</syntaxhighlight>

{{ out }}

<pre>

The longest rep-strings are:

1001110011 -> 10011

1110111011 -> 1110

0010010010 -> 001

1010101010 -> 1010

1111111111 -> 11111

0100101101 -> Not a rep-string

0100100 -> 010

101 -> Not a rep-string

11 -> 1

00 -> 0

1 -> Not a rep-string

</pre>