1、第 二 章 C+简单程序设计2-10 执行完下列语句后，a、b、c 三个变量的值为多少？a = 30;b = a+;c = +a;a：32 ； b：30 ； c：32 ；2-13 写一条 for 语句，计数条件为 n从 100 到 200，步长为 2；然后用 while和 dowhile 语句完成同样的循环。解： for 循环：for (int n = 100; n void main()int iint j;i = 10; /* 给 i 赋值j = 20; /* 给 j 赋值 */cout int main()int i;int j;i = 10; / 给 i 赋值j = 20; /* 给
2、j 赋值 */cout int main()int i;cout i;cout int main()for (int i = 32; i?ABCDEFGHIJKLMNOP_QRSTUVWXYZabcdefghijklmnopqrstuvwxyzs2-21 运行下面的程序，观察其输出，与你的设想是否相同？#include int main()unsigned int x;unsigned int y = 100;unsigned int z = 50;x= y - z;cout int main()int myAge = 39; / initialize two integersint your
3、Age = 39;cout #include void main()char flag;while(1)cout flag;if ( toupper(flag) = Y)cout void main()int i,score;cout score;if (score100 | score#include void main()int i,j,k,flag;i = 2;while(i #include void main()int i,j,k,flag;i = 2;doflag = 1;k = sqrt(i);j = 2;doif(i%j = 0)flag = 0;break;j+;while
4、(j #include void main()int i,j,k,flag;for(i = 2; i void main() int n = 18;int m = 0;while(m != n) cout m;if (n m)cout void main() int n = 18;int m = 0;docout m;if (n m)cout int main()int intOne;int intOne = 5;cout short int Divider(unsigned short int a, unsigned short int b)if (b = 0)return -1;elser
5、eturn a/b;typedef unsigned short int USHORT;typedef unsigned long int ULONG;int main()USHORT one, two;short int answer;cout one;cout two;answer = Divider(one, two);if (answer -1)cout #include int fn1(int i,int j); /求最大公约数的函数void main()int i,j,x,y;cout i ;cout j ;x = fn1(i,j);y = i * j / x;cout #incl
6、ude int fn1(int i);void main()int i;cout i ;cout 2; fib(1) = fib(2) = 1;观察递归调用的过程。解： 源程序见“实验指导“部分实验三3-15 用递归的方法编写函数求 n 阶勒让德多项式的值，在主程序中实现输入、输出；解： #include float p(int n, int x);void main()int n,x;cout n;cout x;cout class Rectanglepublic:Rectangle (int top, int left, int bottom, int right);Rectangle (
7、) int GetTop() const return itsTop; int GetLeft() const return itsLeft; int GetBottom() const return itsBottom; int GetRight() const return itsRight; void SetTop(int top) itsTop = top; void SetLeft (int left) itsLeft = left; void SetBottom (int bottom) itsBottom = bottom; void SetRight (int right) i
8、tsRight = right; int GetArea() const;private:int itsTop;int itsLeft;int itsBottom;int itsRight;Rectangle:Rectangle(int top, int left, int bottom, int right)itsTop = top;itsLeft = left;itsBottom = bottom;itsRight = right;int Rectangle:GetArea() constint Width = itsRight-itsLeft;int Height = itsTop -
9、itsBottom;return (Width * Height);int main()Rectangle MyRectangle (100, 20, 50, 80 );int Area = MyRectangle.GetArea();cout class Rectanglepublic:Rectangle(float len, float width)Length = len;Width = width;Rectangle();float GetArea() return Length * Width; float GetLength() return Length; float GetWi
10、dth() return Width; private:float Length;float Width;void main()float length, width;cout length;cout width;Rectangle r(length, width);cout class datatypeenumcharacter,integer,floating_point vartype;union char c;int i;float f;public:datatype(char ch) vartype = character;c = ch;datatype(int ii) vartyp
11、e = integer;i = ii;datatype(float ff) vartype = floating_point;f = ff;void print();void datatype:print() switch (vartype) case character:cout class Circlepublic:Circle(float radius) Radius = radius;Circle()float GetArea() return 3.14 * Radius * Radius; private:float Radius;void main()float radius;co
12、ut radius;Circle p(radius);cout class Tree int ages;public:Tree(int n=0);Tree();void grow(int years);void age();Tree:Tree(int n) ages = n;Tree:Tree() age();void Tree:grow(int years) ages += years;void Tree:age() cout void fn1()static int n = 0;n+;cout i =+10; void Y:g(X* x) x-i +; class Z public:voi
13、d f(X* x) x-i += 5; ;#endif / MY_X_Y_Z_H程序运行输出：无5-14 定义 Boat 与 Car 两个类，二者都有 weight 属性，定义二者的一个友元函数 totalWeight()，计算二者的重量和。解： 源程序：#include class Boat;class Carprivate:int weight;public:Car(int j)weight = j;friend int totalWeight(Car ;class Boatprivate:int weight;public:Boat(int j)weight = j;friend int
14、 totalWeight(Car ;int totalWeight(Car void main()Car c1(4);Boat b1(5);cout int main()int myArray5;int i;for ( i=0; i myArrayi;for (i = 0; i#include int count(char *str)int i,num=0;for (i=0; stri; i+)if ( (stri=a for(i = 0; si != 0; i+)for(j = i, k = 0; tk != 0 j+, k+);if (tk =0)return i;return -1;vo
15、id main()int n;char str120,str220;cout str1;cout str2;n = index(str1,str2);if (n 0)cout class BaseClasspublic:BaseClass();BaseClass:BaseClass()cout #include class Documentpublic:Document();Document( char *name );char *Name; / Document name.void PrintNameOf(); / Print name.;Document:Document( char *n
16、ame )Name = new char strlen( name ) + 1 ;strcpy( Name, name );void Document:PrintNameOf()cout class objectprivate:int Weight;public:object() cout class BaseClasspublic:void fn1();void fn2();void BaseClass:fn1()cout fn1();pBaseClass-fn2();pDerivedClass-fn1();pDerivedClass-fn2();程序运行输出：调用派生类的函数 fn1()调用派生类的函数 fn2()调用基类的函数 fn1()调用基类的函数 fn2()调用派生类的函数 fn1()调用派生类的函数 fn2()
