public class Demo2 {

public static void main(String[] args) {

// TODO Auto-generated method stub

/*

FileReader fr = null;

FileWriter fw = null;

try {

fr = new FileReader("c:/1.txt");

fw = new FileWriter("c:/2.txt");

char[] cbuf = new char[1024];

int ln;

while ( ( ln = fr.read(cbuf)) != -1) {

cbuf = String.valueOf(cbuf, 0, ln).toCharArray();

fw.write(cbuf);

}

} catch (FileNotFoundException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

} finally {

try {

fr.close();

fw.close();

} catch (IOException e) {

// TODO Auto-generated catch block

e.printStackTrace();

}

}

*/

/*

HashMap<Integer, HashMap<Integer, HashSet<Integer>>> gen = new HashMap<Integer, HashMap<Integer, HashSet<Integer>>>();

int i = 1;

while (i < 7) {

int b = 1;

HashMap<Integer, HashSet<Integer>> cls = null;

while (b < 11) {

int c = 1;

cls = new HashMap<Integer, HashSet<Integer>>();

HashSet<Integer> na = new HashSet<Integer>();

while (c < 51) {

na.add(c);

c++;

}

cls.put(b, na);

b++;

}

gen.put(i, cls);

i++;

}

//    HashMap<Integer, HashMap<Integer, HashSet<Integer>>>

for (Integer integer : gen.keySet()) {

HashMap<Integer, HashSet<Integer>> hs = gen.get(integer);

for (Entry<Integer, HashSet<Integer>>  tt : hs.entrySet()) {

StringBuffer bu = new StringBuffer();

for (Integer integer2 : tt.getValue()) {

bu.append("第 " + integer2 + " 人  ");

}

System.out.println(integer +"年级  "+tt.getKey() + "班    " +  "第 "+ bu + "\n");

}

}

*/