C++ STL入门教程(7) multimap、multiset的使用

/*请务必运行以下程序后对照阅读*/  ///头文件依旧是map #include <map> #include <string> #include <iostream> using namespace std;  int main() {   ///1. 初始化   multimap<int, string> mapStudent;   multimap<int, string>::iterator iter, beg, end;      ///2. 添加元素   ///multimap不支持下标操作   mapStudent.insert(pair<int, string>(0, "student_one"));   mapStudent.insert(pair<int, string>(0, "student_one_copy"));///一对多   mapStudent.insert(pair<int, string>(1, "student_two"));   mapStudent.insert(pair<int, string>(5, "Fear Kubrick"));   mapStudent.insert(pair<int, string>(2, "Akemi Homura"));   mapStudent.insert(pair<int, string>(-1, "Eren Jaeger"));   mapStudent.insert(pair<int, string>(99, "lin"));   cout << mapStudent.size() << endl;   cout << endl;      ///3. 遍历   for (iter = mapStudent.begin(); iter != mapStudent.end(); iter++)     cout << iter->first << " " << iter->second << endl;   cout << endl;      ///4. 单键查询与范围查询   ///单键查询   int count = mapStudent.count(0);   iter = mapStudent.find(0);   for (int i = 0; i < count; i++, iter++)     cout << iter->first << " " << iter->second << endl;   cout << endl;   ///范围查询   beg = mapStudent.lower_bound(1);/// >=1   end = mapStudent.upper_bound(5);/// <=5   for (; beg != end; beg++)     cout << beg->first << " " << beg->second << endl;   cout << endl;      ///5. 删除   iter = mapStudent.find(1);   mapStudent.erase(iter);   cout << mapStudent.size() << endl;   for (iter = mapStudent.begin(); iter != mapStudent.end(); iter++)     cout << iter->first << " " << iter->second << endl;   cout << endl;      ///6. 判空与清空   if (!mapStudent.empty())     mapStudent.clear(); } 

/*请务必运行以下程序后对照阅读*/  ///头文件依旧为set #include <set> #include <iostream> using namespace std;  int main() {   ///1. 初始化   multiset<int> num;   multiset<int>::iterator iter,beg,end;   cout << num.max_size() << endl;///multiset容纳上限   cout << endl;    ///2. 添加元素   for (int i = 0; i < 10; i++)     num.insert(i);   cout << num.size() << endl;   cout << endl;    ///3. 遍历   for (iter = num.begin(); iter != num.end(); iter++)     cout << *iter << " " ;   cout << endl;   cout << endl;    ///4. 查询    iter = num.find(1);   if (iter != num.end())     cout << *iter << endl;   else     cout << -1 << endl;    iter = num.find(99);   if (iter != num.end())     cout << *iter << endl;   else     cout << -1 << endl;   cout << endl;    beg=num.lower_bound(2);   end=num.upper_bound(7);   for (; beg != end; beg++)     cout << *beg << " " ;   cout << endl;    ///5. 删除   iter = num.find(1);   num.erase(iter);   cout << num.size() << endl;   for (iter = num.begin(); iter != num.end(); iter++)     cout << *iter << " " ;   cout << endl;   cout << endl;    ///6. 判空与清空   if (!num.empty())     num.clear(); }