C++程序设计教程(修订版)——设计思想与实现习题解答钱能
二
2.1
#include
void main()
{ //本题原考虑在 16 位机器上实验目前多为 32 位机器故已过时。int a = 42486; cout < cout << dec <<(signed)b < } 2.2 #include #include double pi = 3.1415926; void main() { double radius1, radius2; cout <<"please input two numbers:\n"; cin >>radius1 >>radius2; cout < <<(pi*radius1*radius1) < < < } 2.3 #include 2.718281828; void main() { cout < < < } 2.4 #include void main() { cout <<"\"How many students here?\"\n" <<"\"500\"\n"; } 2.5 #include void main() { cout <<"size of char " < unsigned char " < <<"size of signed char " < <<"size of unsigned " < byte\n" <<"size of unsigned short " < of long " < <<"size of signed long " < <<"size of unsigned long " < <<"size of double " < <<"size of long double " < } 2.6 1) please input 3 sides of one triangle: 6,6,8 a= 6.00,b= 6.00,c= 8.00 area of triangle is 17.88854 2) 该程序计算三角形的面积前后分为三部分输入处理输出。 3) //#include #include void main() { float a,b,c,s,area; //printf("please input 3 sides of one triangle:\n"); cout <<"please input 3 sides of one triangle:\n"; //scanf("%f,%f,%f",&a,&b,&c); // 输入时以逗号作为数据间隔 cin >>a >>b >>c; //输入时以空格作为数据间隔 s=(a+b+c)/2; area=sqrt(s*(s-a)*(s-b)*(s-c)); //printf("a=%7.2f,b=%7.2f,c=%7.2f\n",a,b,c); cout < <<"area of triangle is " < < } 4) #include float area(float a, float b, float c); // 函数声明 void main() { float a,b,c; cout <<"please input 3 sides of one triangle:\n"; cin >>a >>b >>c; //输入时以空格作为数据间隔 float result = area(a,b,c); //函数调用 cout < < < } float area(float a, float b, float c) // 函数定义 { float s=(a+b+c)/2; return sqrt(s*(s-a)*(s-b)*(s-c)); } 2.7 In main(): Enter two numbers: 3 8 Calling add(): In add(),received 3 and 8 and return 11 Back in main(): c was set to 11 Exiting... 2.8 #include { double radius, height; cout <<"请输入圆柱体的半径和高:\n"; cin >>radius >>height; double volume = Cylinder(radius, height); cout <<"该圆柱体的体积为 " < } double Cylinder(double r, double h) { return r*r*M_PI*h; } 三 3.1 (1)sqrt(pow(sin(x),2.5)) (2)(a*x+(a+x)/(4*a))/2 (3)pow(c,x*x)/sqrt(2*M_PI) //M_PI 为 BC 中 math.h 中的圆周率常数 3.2 13.7 2.5 9 3.3 (1)a1=1 a2=1 (2) 1.1 (3) 2,0.0 (4) 20 3.4 #include void main() { int x; cout <<"please input x:\n"; cin >>x; if(x<=-1) cout <<(x-1) < && x<=2) cout <<2*x < if(2 cout < } 3.5 #include void main() { int a; cout <<"please input a number:\n"; cin >>a; int c1 = a%3 ==0; int c2 = a%5 ==0; int c3 = a%7 ==0; switch((c1<<2)+(c2<<1)+c3){ case 0: cout <<" 不能被3,5,7 整除.\n"; break; case 1: cout <<"只能被7 整除.\n"; break; case 2: cout <<"只能被 5 整除.\n"; break; case 3: cout <<" 可以被5,7 整除.\n"; break; case 4: cout <<" 只能被3 整除.\n"; break; case 5: cout <<" 可以被3,7 整除.\n"; break; case 6: cout <<"可以被3,5 整除.\n"; break; case 7: cout <<"可以被3,5,7 整除.\n"; break; } } 3.6 #include void main() { int grade; cout <<"please input a number:\n"; cin >>grade; if(grade>100||grade<0) cout <<"错误的成绩.\n"; else if(grade>=90) cout <<"A.\n"; else if(grade>=80) cout <<"B.\n"; else if(grade>=70) cout <<"C.\n"; else if(grade>=60) cout <<"D.\n"; else cout <<"E.\n"; } 四4.1 1 #include void main() { double sum=1, t=-1, x; int i=1; cout <<"please input a value:\n"; cin >>x; do{ t*=(-1)*x/i; sum+=t; i++; }while(fabs(t)>1e-8); cout <<"sum=" < } 2 #include #include main() { double sum=1, t=-1, x; cout <<"please input a value:\n"; cin >>x; int i=1; while(fabs(t)>1e-8){ t*=(- 1)*x/i; sum+=t; i++; } cout <<"sum=" < } 3 #include #include main() { double sum=1, t=-1, x; cout <<"please input a value:\n"; cin >>x; for(int i=1; fabs(t)>1e-8; i++){ t*=(-1)*x/i; sum+=t; } cout <<"sum=" < } 4.2 #include void main() { long sum=0, t=1; for(int i=1; i<=15; i++){ t*=i; sum+=t; } cout <<"sum=" < } 4.3 #include void main() { for(int i=1; i<=9; i++) for(int j=0; j<=9; j++) for(int k=0; k<=9; k++) if(i*i*i+j*j*j+k*k*k == 100*i+10*j+k) cout <<(100*i+10*j+k) <<"是水仙花数 .\n"; } 4.4 #include void main() { for(int i=1; i<1000; i++){ int sum=0; for(int j=1; j<=i/2; j++) if(i%j==0) sum+=j; if(sum==i) cout < 是完 数 .\n"; } } 4.5 #include void main() { float s=100,h=100; for(int i=1; i<10; i++){ s+=h; h/=2; } cout <<" 共经过" < } 4.6 #include main() { int peachs=1; for(int i=1; i<10; i++) peachs=(peac hs+1)*2; cout <<" 第一天共摘下" < } 4.7 #include void main() { double x, a; cout <<"please input a value:\n"; cin >>a; x = a/2; while(fabs((x-a/x)/2)>1e-7) x=(x+a/x)/2; cout < 的平方根是" < } 4.8 1 #include void main() { for(int i=1; i<=10; i++){ for(int j=1; j<=10-i; j++) cout <<" "; for(int j=1; j<=2*i- 1; j++) cout <<"#"; cout < } 2 #include void main() { for(int i=1; i<=8; i++){ for(int j=1; j<=i; j++) cout <<" "; for(int j=1; j<=18-i; j++) cout <<"#"; cout < } } 4.9 1 #include void main() { cout <<" *"; for(int i=1; i<=9; i++) cout < cout <<"\n-----------------------------------------\n"; for(int i=1; i<=9; i++){ cout < } } 2 #include void main() { cout <<" *"; for(int i=1; i<=9; i++) cout < cout <<"\n-----------------------------------------\n"; for(int i=1; i<=9; i++){ cout < } } #include #include void main() { cout <<" *"; for(int i=1; i<=9; i++) cout < < cout <<"\n-----------------------------------------\n"; for(int i=1; i<=9; i++){ cout < if(i!=1) cout < for(int j=i; j<=9; j++) cout < } } 4.10 #include void main() { int n; long a=1, b=1, c=1, temp; cout <<"please input a value:\n"; cin >>n; for(int i=4; i<=n; i++){ temp=a+c; a=b; b=c; c=temp; } cout << c < } 五 5.1 #include #include #include isprime(long n); void main() { //input long a,b,l=0; cout <<"please input two numbers:\n"; cin >>a >>b; cout <<"primes from " < for(long m=a; m<=b; m+=2) if(isprime(m)){ //output