/s1:{0,1,2,3,4,5,6,7,8,9y /s4:{7,8,9y index=sl.subSet(s4);/判断s1是否为s4子集 cout<<index<<endl;/结果，index=O equal (s1 =s2); /集合S1与S2比较相等 cout<<equal<<endl;/为0，两集合不等 11//s1: {0, 1, 2, 3, 4, 5, 6, 7, 8, 9} //s4: {7, 8, 9} index = s1.subSet (s4); //判断s1是否为s4子集 cout << index << endl; //结果，index = 0 equal = (s1 == s2); //集合s1与s2比较相等 cout << equal << endl; //为0, 两集合不等 11