CareerCup

HashSet set = new HashSet();
StringBuilder str = new StringBuilder();
while(i<string.length){
while(i<string.length&&string.charAt(i)!=' '){
str.append(string.charAt(i++));
}
set.add(str.toString());
while(i<string.length() && string.charAt(i)==' '){
i++;
}
str.delete(0,str.length());
}

List<char> Split(string str)
{
List<char> l = new List<char>();

foreach (char ch in str)
{
if (l.Contains(ch) || ch == ' ')
continue;
else
l.Add(ch);
}

return l;
}

//For words which are non duplicate
eg :- "This is a string which is duplicate"
ans: this
a
string
which
duplicate

static void printUniqueWords(String string){
		List<String> list = new ArrayList<String>();
		int map[]=new int[string.length()];
		int start =0;int k =0;
		for (int i = 0; i <= string.length(); i++) {
			if(i == string.length() || string.charAt(i)== ' '){
				if((k = list.indexOf(string.substring(start, i)))!= -1)
					map[k] = 1;
				else list.add(string.substring(start, i));
				start = i+1;
			}
		}
		for (int i = 0; i < list.size(); i++) {
			if(map[i] != 1)
			System.out.println(list.get(i));
		}
	}

we can use a trie here ..