Determine if a string has all unique characters: Difference between revisions
Determine if a string has all unique characters (view source)
Revision as of 16:18, 27 May 2023
, 1 year agoNew post, showing Java 11 syntax, in addition to existing Java post.
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(New post, showing Java 11 syntax, in addition to existing Java post.) |
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XYZ ZYX 7 no 'Z' 5A 3 5
1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ 36 no '0' 30 10 25
</pre>
===Using Java 11===
<syntaxhighlight lang="java">
import java.util.HashSet;
import java.util.List;
import java.util.OptionalInt;
import java.util.Set;
public final class DetermineUniqueCharacters {
public static void main(String[] aArgs) {
List<String> words = List.of( "", ".", "abcABC", "XYZ ZYX", "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" );
for ( String word : words ) {
Set<Integer> seen = new HashSet<Integer>();
OptionalInt first = word.chars().filter( i -> ! seen.add(i) ).findFirst();
if ( first.isPresent() ) {
final char ch = (char) first.getAsInt();
final String hex = Integer.toHexString(ch).toUpperCase();
System.out.println("Word: \"" + word + "\" contains a repeated character.");
System.out.println("Character '" + ch + "' (hex " + hex + ") occurs at positions "
+ word.indexOf(ch) + " and " + word.indexOf(ch, word.indexOf(ch) + 1));
} else {
System.out.println("Word: \"" + word + "\" has all unique characters.");
}
System.out.println();
}
}
}
</syntaxhighlight>
{{ out }}
<pre>
Word: "" has all unique characters.
Word: "." has all unique characters.
Word: "abcABC" has all unique characters.
Word: "XYZ ZYX" contains a repeated character.
Character 'Z' (hex 5A) occurs at positions 2 and 4
Word: "1234567890ABCDEFGHIJKLMN0PQRSTUVWXYZ" contains a repeated character.
Character '0' (hex 30) occurs at positions 9 and 24
</pre>
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