map容器说明和使用技巧与实例.doc

C++中map容器的说明和使用技巧 HYPERLINK JavaScript:d=document;t=d.selection?(d.selection.type!=None?d.selection.createRange().text:):(d.getSelection?d.getSelection():);void(saveit=window.open(/storeit.aspx?t=+escape(d.title)+u=+escape(d.location.href)+c=+escape(t),saveit,scrollbars=no,width=590,height=300,left=75,top=20,status=no,resizable=yes));saveit.focus(); \o 收藏到我的网摘中，并分享给我的朋友 收藏 C++中map容器提供一个键值对容器，map与multimap差别仅仅在于multiple允许一个键对应多个值。??? 一、map的说明??? 1?? 头文件?? #include?? map???? 2?? 定义?? mapstring,?? int?? my_Map;?? 或者是typedef???? mapstring,?? int?? MY_MAP;?? MY_MAP?? my_Map;???? 3?? 插入数据?? (1)?? my_Map[a]?? =?? 1;?? (2)?? my_Map.insert(mapstring,?? int::value_type(b,2));?? (3)?? my_Map.insert(pairstring,int(c,3));?? (4)?? my_Map.insert(make_pairstring,int(d,4));???? 4?? 查找数据和修改数据?? (1)?? int?? i?? =?? my_Map[a];???????????? my_Map[a]?? =?? i;?? (2)?? MY_MAP::iterator?? my_Itr;???????????? my_Itr.find(b);???????????? int?? j?? =?? my_Itr-second;???????????? my_Itr-second?? =?? j;?? 不过注意，键本身是不能被修改的，除非删除。???? 5?? 删除数据?? (1)?? my_Map.erase(my_Itr);?? (2)?? my_Map.erase(c);?? 还是注意，第一种情况在迭代期间是不能被删除的，道理和foreach时不能删除元素一样。???? 6?? 迭代数据?? for?? (my_Itr=my_Map.begin();?? my_Itr!=my_Map.end();?? ++my_Itr)?? {}???? 7?? 其它方法?? my_Map.size()?????????????? 返回元素数目?? my_Map.empty()?????? 判断是否为空?? my_Map.clear()?????????? 清空所有元素?? 可以直接进行赋值和比较：=,?? ,?? =,?? ,?? =,?? !=?? 等等???? 更高级的应用查帮助去吧，^_^; 二\map的举例 要求: 将mymap中itemstruct?? 的a大于100的项删除??struct?? itemstruct?? {???????????? int?? a;???????????? char?? b[20];?? };?? mapstring,?? itemstruct?? ???? mymap.???解答1:? #include?? iostream?? #include?? ctime?? #include?? map?? using?? namespace?? std;?? typedef?? struct?? itemstruct?? {???????????? int?? a;???????????? char?? b[20];?? }itemS;?? itemS?? s[4]?? =?? {{102,what},?????????????????????????? {33,?? hello},?????????????????????????? {198,world},?????????????????????????? {45,?? c++}?????????????????????? };;?????? int???? main()