Given an array of html as strings, print all the tags separated by ; lexicographically. Omit duplicates.

HTMLTagsDetection.java

public class HTMLTagsDetection {
	public static String toStringLexicographically(String[] htmls){
		HashSet<String> tags= new HashSet<String>();
		for(int i=0;i<htmls.length;i++){
			detect(tags, htmls[i]);
		}
		String[] sorted=new String[tags.size()];
		tags.toArray(sorted);
		Arrays.sort(sorted);
		return implodeArray(sorted,";");
	}
	private static void detect(HashSet<String> tags, String html){
		for(int i=0;i<html.length();i++){
			if(html.charAt(i)=='<'){
				i++;
				StringBuilder sb= new StringBuilder();
				while(i<html.length() && html.charAt(i)==' ') i++;
				while(i<html.length() &&  html.charAt(i)!=' ' && html.charAt(i)!='>' && html.charAt(i)!='/'){
					sb.append(html.charAt(i));
					i++;
				}
				if(sb.length()!=0)
					tags.add(sb.toString());
			}
		}
	}
	public static String implodeArray(String[] inputArray, String glueString) {
		if (inputArray.length > 0) {
			StringBuilder sb = new StringBuilder();
			sb.append(inputArray[0]);

			for (int i=1; i<inputArray.length; i++) {
				sb.append(glueString);
				sb.append(inputArray[i]);
			}

			return sb.toString();
		}
		return "";
	}	
}

HTMLTagsDetectionTest.java

public class HTMLTagsDetectionTest {
	@Test
	public void testToStringLexicographically() {
		assertEquals("a;div;p", HTMLTagsDetection.toStringLexicographically(new String[]{"<p><a href=\"http://www.quackit.com/html/tutorial/html_links.cfm\">Example Link</a></p>","<div class=\"more-info\"><a href=\"http://www.quackit.com/html/examples/html_links_examples.cfm\">More Link Examples...</a></div>"}));	
	}
}