計算機相關(guān)2013晶實例

1、C+C+實例實例王雪晶例1：單詞和詞典類n建立一個由單詞及其含義組成的類Definition(每個單詞最多有10條含義),并使用該類的對象實現(xiàn)單詞及其含義的輸入輸出。n建立一個詞典，詞典由一個一個單詞組成，故Dictionary類中包含了Definition類的對象數(shù)組（可存放100個單詞）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()單詞類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()詞典類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=“班級班級”，“類類”，“階級階級”，“課課”，“等等級級”，0;char * word2=“object”;char * indef2=“目的目的”，“對象對象”，“物體物體”，“賓語賓語”，“客觀客觀”，0;char * word3=“snow”;char * indef3=“雪雪”，“雪花效應雪花效應”，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：鏈表n建立鏈表項Itemn一個數(shù)據(jù)項datan一個指針*next例2：鏈表n有關(guān)鏈表操作的類Listn顯示輸出一個已生成的鏈表;n對一個空表插入鏈表項，插入項放在表頭；n對一個空表追加鏈表向，追加項放在表尾；n兩個鏈表相連接；n將一個鏈表的各鏈表項逆向輸出；n求得一個鏈表的數(shù)據(jù)項數(shù)。#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“l(fā)ist1: ”;list1.print();List list2;for(i=15;i20;i+)list2.append(i);cout“l(fā)ist2: ”;list2.print();cout“l(fā)ist1 length: ”list1.length()endl;list2.cat(list1);cout“l(fā)ist2: ”;list2.print();list2.reverse

16、();cout“l(fā)ist2: ”;list2.print();cout“l(fā)ist2 length: ”list2.length()endl;例3：虛函數(shù)例子n計算不同幾何形狀的面積和體積n類層次結(jié)構(gòu)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輸出結(jié)果：輸出結(jié)果：endl;cout正方體表面積：正方體表面積：surface_area()endl;cout正方體體積：正方體體積：volume()endl;p=&obj2;cout球體表面積：球體表面積：surface_area()endl;cout球體體積：球體體積：volume()endl;p=&obj1;p=&obj3;cout圓柱體表面積：圓柱體表面積：surface_area()endl;cout圓柱體體積：圓柱體體積：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類的使用void some_fct()Ival_box* p1 = new Ival_slider(0,5); interact(p1);Ival_box* p2 = new Ival_dial(1,12);interact(p2);一個傳統(tǒng)的層次結(jié)構(gòu)問題：從哪獲取圖形要素？大部分圖形用戶界面系統(tǒng)都提供了一個類，其中定義了屏幕實體的基本性質(zhì)

21、。圖示：BBWindowIval_boxIval_sliderIval_dialPopup_ival_sliderFlashing_ival_slider一個傳統(tǒng)的層次結(jié)構(gòu)存在問題：1. 版本問題，不同用戶界面系統(tǒng)的Ival_box共存。2. 每個派生類都共享著在Ival_box里聲明的基本數(shù)據(jù)。3. 類BBwindow的修改將迫使Ival_box用戶重新編譯。抽象類重新設(shè)計類層次結(jié)構(gòu)：1. 圖形用戶界面系統(tǒng)是一個實現(xiàn)細節(jié)，對于用戶應是隱蔽的。2. Ival_box類中不包含數(shù)據(jù)。3. 圖形用戶界面系統(tǒng)修改后，不應該重新編譯那些使用Ival_box的代碼。4. 針對不同圖形用戶界面系統(tǒng)的Iva

22、l_box在程序中共存。抽象類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() /虛析構(gòu)函數(shù); 把Ival_box定義為抽象界面抽象類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; 抽象類void f(Ival_box* p)/ .delete p; 保證正確的清理方式是在基類里定義一個虛析構(gòu)函數(shù)Ival_box: Ival_box，并在派

24、生類適當?shù)馗采w它。許多類都需要在它的對象消失之前做些清理工作。抽象類BBWindowIval_boxIval_sliderIval_dialPopup_sliderFlashing_sliderBBWindow圖示：Ival_box的層次結(jié)構(gòu)如下：其它實現(xiàn)方式class Ival_box /* . */ ;/ commonclass Ival_slider : public Ival_box, protected BBwindow /* . */ ; class Ival_slider : public Ival_box, protected CWwindow /* . */ ; 沒有解決版本

25、問題：而且針對不同圖形用戶界面系統(tǒng)的Ival_slider的共存問題。其它實現(xiàn)方式BBwindowIval_boxBB_ival_sliderCWwindowCW_ival_slider圖示：方案：采用不同的名字，定義幾個Ival_sliderclass Ival_box /* . */ ;/ commonclass BB_ival_slider : public Ival_box, protected BBwindow /* . */ ; class CW_ival_slider : public Ival_box, protected CWwindow /* . */ ;其它實現(xiàn)方式BBw

26、indowIval_sliderBB_ival_sliderCWwindowCW_ival_sliderIval_box進一步將面向應用的Ival_box類與實現(xiàn)細節(jié)分開，從Ival_box派生出一個抽象的Ival_slider類。其它實現(xiàn)方式BBsliderIval_sliderBB_ival_sliderCWsliderCW_ival_sliderIval_boxBBwindowCWwindow通常還可以利用實現(xiàn)層次方面的一些更特殊的類。其它實現(xiàn)方式完整的層次結(jié)構(gòu)是將原來面向應用的概念層次結(jié)構(gòu)當作界面而組成的。Ival_boxIval_sliderIval_dialPopup_ival_s

27、liderFlashing _ival_slider其它實現(xiàn)方式針對各種圖形用戶界面系統(tǒng)的實現(xiàn)。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 /* . */ 其它實現(xiàn)方式BBsliderIval_sliderBBipopIval_dialipopupiflashCWipopCWslIval_boxBBsliderBBisliderBBiflCWiflCWslBBb&wCWisliderCWsl完整的層次結(jié)構(gòu)圖示：對象創(chuàng)建的局部化應用中，可以利用Ival_box、Ival_slider等界面寫出。對象的創(chuàng)建必須通過特定于實現(xiàn)的名字。如：創(chuàng)建CW_ival_dial和BB_flashing