交集、並集、差集實現代碼

//交集
Set s1 = new HashSet();
s1.add("aa");
s1.add("bb");
s1.add("cc");
s1.add("dd");
Set s2 = new HashSet();
s2.add("aa");
s2.add("bb");
s2.add("ee");
s2.add("ff");
Set result = new HashSet();
result.addAll(s1);
result.retainAll(s2);
System.out.println("交集begin");
for(String res : result) {
System.out.println(res);
}
System.out.println("交集end");
//並集
Set result2 = new HashSet();
result2.addAll(s1);
result2.addAll(s2);
System.out.println("並集begin");
for(String res : result2) {
System.out.println(res);
}
System.out.println("並集end");
//差集
Set result3 = new HashSet();
result3.addAll(s1);
result3.removeAll(s2);
System.out.println("差集begin");
for(String res : result3) {
System.out.println(res);
}
System.out.println("差集end");