计算机相关2013晶实例

1、C+C+实例实例王雪晶例1：单词和词典类n建立一个由单词及其含义组成的类Definition(每个单词最多有10条含义),并使用该类的对象实现单词及其含义的输入输出。n建立一个词典，词典由一个一个单词组成，故Dictionary类中包含了Definition类的对象数组（可存放100个单词）Definitionword: char *meaningsMAXMEANS: char*nMeanings: intDefinition()Definition(char * word, char * def)operator=(Definition& def): Definition&

2、PutWord(char *s): void GetWord(): char * AddMeaning(char *s): void GetMeaning(int level): char * GetnMeans(): intprint(): voidDefinition()单词类class Definitionpublic:Definition() Definition(char * word, char * def)Definition & operator=(Definition& def)void PutWord(char *s)char * GetWord() ret

3、urn word;void AddMeaning(char *s)char * GetMeaning(int level) return nMeanings;int GetnMeans()void print()Definition()private:char * wordchar * meaningsMAXMEANSint nMeaningsDefiniton:Definition(char * w, char* def)int n=strlen(w)+1;word = new charn;strcpy(word,w);nMeanings = 0;for(; defnMeanings&

4、;nMeanings!=MAXMEANS; nMeanings+)meaningnMeanings = new charstrlen(defnMeanings)+1;strcpy(meaningsnMeanings, defnMeannings);Definiton& Definition:operator = ( Definition& def)int n=strlen(def.word)+1;word = new charn;strcpy(word,def.word);nMeanings = def.nMeanings;for(int i=0; inMeanings; i+

5、)meaningi = new charstrlen(def.meaningsi)+1;strcpy(meaningsi, def.meanningsi); Definition: Definition()delete word;for(int i=0; inMeanings; i+) delete meaningsi;void Definition: PutWord(char *s)int n=strlen(s)+1;word = new charn;nMeanings = 0;void Definition: AddMeaning(char *s)if ( nMeaningsMAXMEAN

6、S)meaningi = new charstrlen(s)+1;strcpy(meaningsnMeanings+, s);char * Definiton:GetMeaning(int level)if (0= level & level nMeanings)return meaningslevel;elsereturn NULL;void Definition: print()cout endlword“:n”;for (int i=0; inMeanings; i+)cout “ ”meaningsiendl;DictionarynWord: long maxWords: lo

7、ngword: Definition* Dictionary (int n=100)FindWord (char * s): longAddWord (Definition& word): voidGetDef (char* word, char* def): intPrint (char *): voidDictionary()词典类Dictionary:Dictionary (int n)nWords = 0;maxWords = n;words = new Definitionn;Dictionary:Dictionary ()deletewords;long Dictionar

8、y:FindWord (char *s)for(int i=0; inWords; i+)if(strcmp(wordsi.Getword(), s)=0)return i;return -1;void Dictionary:AddWord (Definition& word)if (nWordsmaxWords)wordsnWords=word;+nWords;int Dictionary:GetDef (char *word, char* def)int nM=0;int wordIdx = FindWord(word);if (wordIdx!= -1) nM=wordsword

9、Idx.GetnMeans();for(int i=0; inM; i+) char * pMeaning = wordswordIdx.GetMeaning(i); int length = strlen(pMeaning); delete defi; defi = new charlength+1; strcpy(defi, pMeaning);void Dictionary:print (char * w)int wordIdx = FindWord(w);if (wordIdx!= -1)wordswordIdx.print();elsecout“couldnt find”wendl;

10、void main()Dictionary d(5); char * word1=“class”;char * indef1=“班级班级”，“类类”，“阶级阶级”，“课课”，“等等级级”，0;char * word2=“object”;char * indef2=“目的目的”，“对象对象”，“物体物体”，“宾语宾语”，“客观客观”，0;char * word3=“snow”;char * indef3=“雪雪”，“雪花效应雪花效应”，0;Definition def1(word1, indef1);Definition def2(word2, indef2);Definition def3(w

11、ord3, indef3);d.AddWord(def1);d.AddWord(def2);d.AddWord(def3);d.Print(word1);d.Print(word2);d.Print(word3);例2：链表n建立链表项Itemn一个数据项datan一个指针*next例2：链表n有关链表操作的类Listn显示输出一个已生成的链表;n对一个空表插入链表项，插入项放在表头；n对一个空表追加链表向，追加项放在表尾；n两个链表相连接；n将一个链表的各链表项逆向输出；n求得一个链表的数据项数。#include using namespace std;class List;class It

12、empublic:friend class List;private:Item(int d=0) data=d; next=0;Item * next;int data;class Listpublic:List() list=0;List(int d) list=new Item(d);int print();int insert(int d=0);int append(int d=0);void cat(List & il);void reverse();int length();private:Item * end();Item * list;int List:print()if

13、 (list = 0) cout“emptyn”;return 0;cout“(”;int cnt=0;Item *pt=list;while(pt)if(+cnt%40 = 1 & cnt!=1)coutendl;coutdatanext;coutnext=list;list = pt;return d;int List:append(int d)Item *pt = new Item(d);if(list = 0)list = pt;else(end()-next=pt;return d;Item * List:end( )Item *prv, *pt;for( prv=pt=li

14、st; pt; prv=pt, pt=pt-next);return prv;void List:cat( List& il)Item *pt=il.list;while( pt)append(pt-data);pt=pt-next;void List:reverse()Item *pt,*prv,*tmp;prv=0;pt=list;list=end();while(pt!=list)tmp=pt-next;pt-next=prv;prv=pt;pt=tmp;list-next=prv;int List:length()int cnt=0;Item *pt=list;for( ; p

15、t; pt=pt-next,cnt+);return cnt;void main()List list1;list1.print();for(int i=10;i18; i+)list1.insert(i);cout“list1: ”;list1.print();List list2;for(i=15;i20;i+)list2.append(i);cout“list2: ”;list2.print();cout“list1 length: ”list1.length()endl;list2.cat(list1);cout“list2: ”;list2.print();list2.reverse

16、();cout“list2: ”;list2.print();cout“list2 length: ”list2.length()endl;例3：虚函数例子n计算不同几何形状的面积和体积n类层次结构如下:containercubespherecylinder#includeclass containerprotected:double radius;public:container(double radius)container:radius=radius;virtual double surface_area()=0;virtual double volume()=0;class cube:

17、public containerpublic:cube(double radius):container(radius);double surface_area()return radius*radius*6;double volume()return radius*radius*radius;class sphere:public containerpublic:sphere(double radius):container(radius);double surface_area()return 4*3.1416*radius*radius;double volume()return 3.1

18、416*radius*radius*radius*4/3;class cylinder:public containerdouble height;public:cylinder(double radius,double height):container(radius)cylinder:height=height;double surface_area()return 2*3.1416*radius*(height+radius);double volume()return 3.1416*radius*radius*height;void main()container *p;cube ob

19、j1(10);sphere obj2(6);cylinder obj3(4,5);p=&obj1;cout输出结果：输出结果：endl;cout正方体表面积：正方体表面积：surface_area()endl;cout正方体体积：正方体体积：volume()endl;p=&obj2;cout球体表面积：球体表面积：surface_area()endl;cout球体体积：球体体积：volume()endl;p=&obj1;p=&obj3;cout圆柱体表面积：圆柱体表面积：surface_area()endl;cout圆柱体体积：圆柱体体积：volume()pro

20、mpt(); / alert user/ .int i = pb-get_value();if (pb-was_changed() / new value; do something else / old value was fine/ . Ival_box类的使用void some_fct()Ival_box* p1 = new Ival_slider(0,5); interact(p1);Ival_box* p2 = new Ival_dial(1,12);interact(p2);一个传统的层次结构问题：从哪获取图形要素？大部分图形用户界面系统都提供了一个类，其中定义了屏幕实体的基本性质

21、。图示：BBWindowIval_boxIval_sliderIval_dialPopup_ival_sliderFlashing_ival_slider一个传统的层次结构存在问题：1. 版本问题，不同用户界面系统的Ival_box共存。2. 每个派生类都共享着在Ival_box里声明的基本数据。3. 类BBwindow的修改将迫使Ival_box用户重新编译。抽象类重新设计类层次结构：1. 图形用户界面系统是一个实现细节，对于用户应是隐蔽的。2. Ival_box类中不包含数据。3. 图形用户界面系统修改后，不应该重新编译那些使用Ival_box的代码。4. 针对不同图形用户界面系统的Iva

22、l_box在程序中共存。抽象类class Ival_box public:virtual int get_value() = 0;virtual void set_value(int i) = 0;virtual void reset_value(int i) = 0;virtual void prompt() = 0;virtual bool was_changed() const = 0;virtual Ival_box() /虚析构函数; 把Ival_box定义为抽象界面抽象类class Ival_slider : public Ival_box, protected BBwindow

23、public:Ival_slider(int,int);Ival_slider();int get_value();void set_value(int i);/ .protected:/ functions overriding BBwindow virtual functions/ e.g. BBwindow:draw(), BBwindow:mouse1hit()private:/ data needed for slider; 抽象类void f(Ival_box* p)/ .delete p; 保证正确的清理方式是在基类里定义一个虚析构函数Ival_box: Ival_box，并在派

24、生类适当地覆盖它。许多类都需要在它的对象消失之前做些清理工作。抽象类BBWindowIval_boxIval_sliderIval_dialPopup_sliderFlashing_sliderBBWindow图示：Ival_box的层次结构如下：其它实现方式class Ival_box /* . */ ;/ commonclass Ival_slider : public Ival_box, protected BBwindow /* . */ ; class Ival_slider : public Ival_box, protected CWwindow /* . */ ; 没有解决版本

25、问题：而且针对不同图形用户界面系统的Ival_slider的共存问题。其它实现方式BBwindowIval_boxBB_ival_sliderCWwindowCW_ival_slider图示：方案：采用不同的名字，定义几个Ival_sliderclass Ival_box /* . */ ;/ commonclass BB_ival_slider : public Ival_box, protected BBwindow /* . */ ; class CW_ival_slider : public Ival_box, protected CWwindow /* . */ ;其它实现方式BBw

26、indowIval_sliderBB_ival_sliderCWwindowCW_ival_sliderIval_box进一步将面向应用的Ival_box类与实现细节分开，从Ival_box派生出一个抽象的Ival_slider类。其它实现方式BBsliderIval_sliderBB_ival_sliderCWsliderCW_ival_sliderIval_boxBBwindowCWwindow通常还可以利用实现层次方面的一些更特殊的类。其它实现方式完整的层次结构是将原来面向应用的概念层次结构当作界面而组成的。Ival_boxIval_sliderIval_dialPopup_ival_s

27、liderFlashing _ival_slider其它实现方式针对各种图形用户界面系统的实现。class BB_ival_slider : public Ival_slider, protected BBslider /* . */ ;class BB_flashing_ival_slider : public Flashing_ival_slider,protected BBwindow_with_bells_and_whistles /* . */ ;class BB_popup_ival_slider : public Popup_ival_slider, protected BBsl

28、ider /* . */ ;class CW_ ival_slider : public Ival_slider, protected CWslider /* . */ 其它实现方式BBsliderIval_sliderBBipopIval_dialipopupiflashCWipopCWslIval_boxBBsliderBBisliderBBiflCWiflCWslBBb&wCWisliderCWsl完整的层次结构图示：对象创建的局部化应用中，可以利用Ival_box、Ival_slider等界面写出。对象的创建必须通过特定于实现的名字。如：创建CW_ival_dial和BB_flashing