1.

Četnost

"public class Frequency {


public static final Integer ONE = new Integer(1);


public static void main (String[] args) throws IOException {
Frequency app = new Frequency();
app.run();
}

public void run () throws IOException {

BufferedReader in =
new BufferedReader(new InputStreamReader(System.in));

Map map = new HashMap();
in = new BufferedReader(new InputStreamReader(System.in));


String line = in.readLine();
while (line != null) {
StringTokenizer st = new StringTokenizer(line);
while (st.hasMoreTokens()) {

String word = st.nextToken();
Integer value = (Integer) map.get(word);

if (value == null) {
map.put(word, ONE);
} else {
int val = value.intValue();
map.put(word, new Integer(val+1));
}
}
line = in.readLine();
}

System.out.println(map);
}
}"

Psáno v Poznámkovém bloku. Jedná se o soubor Java.