Initial data commit

Task/Determine-if-a-string-has-all-the-same-characters/Java/determine-if-a-string-has-all-the-same-characters-1.java

@@ -0,0 +1,2 @@
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;

Task/Determine-if-a-string-has-all-the-same-characters/Java/determine-if-a-string-has-all-the-same-characters-2.java

@@ -0,0 +1,30 @@
+public static void main(String[] args) {
+    String[] strings = {
+        "", "   ", "2", "333", ".55", "tttTTT", "5", "4444 444k"
+    };
+    for (String string : strings)
+        System.out.println(printCompare(string));
+}
+
+static String printCompare(String string) {
+    String stringA = "'%s' %d".formatted(string, string.length());
+    Pattern pattern = Pattern.compile("(.)\\1*");
+    Matcher matcher = pattern.matcher(string);
+    StringBuilder stringB = new StringBuilder();
+    /* 'Matcher' works dynamically, so we'll have to denote a change */
+    boolean difference = false;
+    char character;
+    String newline = System.lineSeparator();
+    while (matcher.find()) {
+        if (matcher.start() != 0) {
+            character = matcher.group(1).charAt(0);
+            stringB.append(newline);
+            stringB.append("  Char '%s' (0x%x)".formatted(character, (int) character));
+            stringB.append(" @ index %d".formatted(matcher.start()));
+            difference = true;
+        }
+    }
+    if (!difference)
+        stringB.append(newline).append("  All characters are the same");
+    return stringA + stringB;
+}

Task/Determine-if-a-string-has-all-the-same-characters/Java/determine-if-a-string-has-all-the-same-characters-3.java

@@ -0,0 +1,21 @@
+public class Main{
+	public static void main(String[] args){
+		String[] tests = {"", "   ", "2", "333", ".55", "tttTTT", "4444 444k"};
+		for(String s:tests)
+			analyze(s);
+	}
+
+	public static void analyze(String s){
+		System.out.printf("Examining [%s] which has a length of %d:\n", s, s.length());
+		if(s.length() > 1){
+			char firstChar = s.charAt(0);
+			int lastIndex = s.lastIndexOf(firstChar);
+			if(lastIndex != 0){
+				System.out.println("\tNot all characters in the string are the same.");
+				System.out.printf("\t'%c' (0x%x) is different at position %d\n", firstChar, (int) firstChar, lastIndex);
+				return;
+			}
+		}
+		System.out.println("\tAll characters in the string are the same.");
+	}
+}

Task/Determine-if-a-string-has-all-the-same-characters/Java/determine-if-a-string-has-all-the-same-characters-4.java

@@ -0,0 +1,27 @@
+import java.util.OptionalInt;
+
+public final class AllSameCharacters {
+
+	public static void main(String[] aArgs) {
+		String[] words = { "", "   ", "2", "333", ".55", "tttTTT", "4444 444k" };
+		for ( String word : words ) {
+			analyse(word);
+		}		
+	}
+	
+	private static void analyse(String aText) {
+		System.out.println("Examining \"" + aText + "\", which has length " + aText.length() + ":");
+
+		OptionalInt mismatch = aText.chars().filter( ch -> ch != aText.charAt(0) ).findFirst();		
+		
+		if ( mismatch.isPresent() ) {
+			char fault = (char) mismatch.getAsInt();
+			System.out.println("    Not all characters in the string are the same.");
+			System.out.println("    Character \"" + fault + "\" (" + Integer.toHexString((char) fault)
+			                        + ") is different at index " + aText.indexOf(fault));
+		} else {
+			System.out.println("    All characters in the string are the same.");			
+		}		
+	}
+
+}