c++上机实验答案..doc

实验二答案 题2＿3 #includeiostream #includemath.h using namespace std; void main(void) { int x,y; coutplease input two numbers:endl; coutx=:; cinx; couty=:; ciny; coutendl; coutx+y=x+yendl; coutx-y=x-yendl; coutx*y=x*yendl; if(y==0) cout除数不能为0endl; else coutx/y=x/yendl; coutx%y=x%yendl; system(pause); } 题2＿5 #includeiostream using namespace std; void main(void) { int a=1,b=1,c=3; b+=a+2*c%5; cout表达式b+=a+2*c%5=bendl; a=1;b=1;c=3; a*=b=c=3; cout表达式a*=b=c=3=aendl; a=1;b=1;c=3; a+=b+=c; cout表达式a+=b+=c=aendl; a=1;b=1;c=3; a-=b=++c+2; cout表达式a-=b=++c+2=aendl; system(pause); } 题2＿6 #includeiostream using namespace std; void main(void) { const float pi=3.14; float r=0,c=0,s=0; cout请输入圆的半径r=endl; cinr; c=2*pi*r; s=pi*r*r; cout该圆的周长c=cendl; cout该圆的面积s=sendl; system(pause); }实验三答案 题3-1 #includeiostream #includecmath using namespace std; void main() {double a,b,c,x1,x2; cout请输入方程的系数 a，b，c：; cinabc; if (a==0) { if (b==0) { if (c==0) cout方程有无穷多解endl; else cout方程无解endl; } else coutx=-c/bendl; } else { if ( b*b-4*a*c0 ) coutx1= (-b+sqrt(b*b-4*a*c))/(2*a)endl x2= (-b-sqrt(b*b-4*a*c))/(2*a)endl; else { if(b*b-4*a*c==0) coutx=-b/(2*a)endl; else { double m,n; m=-b/(2*a); n=sqrt(4*a*c-b*b)/(2*a); coutx1=m+niendl x2=m-niendl; } } } system(pause); //本行语句用于程序暂停，以观察输出结果 } 题3-2 #includeiostream using namespace std; void main() { int i,a,b; cout请输入两个整数FirstNum和SecondNum(FirstNum要比SecondNum小)：; cinab; if(a=b) { cout您所输入的两个数不满足条件，请重新输入endl; cout请输入两个整数FirstNum和SecondNum(FirstNum要比SecondNum小)：; cinab; } //两数之间的奇数 couta和b之间的奇数为：endl; for(i=a+1;ib;i++) { if(i%2!=0) coutiendl; } //两数之间的偶数的和 long sum=0; for(i=a+1;ib;i++) { if(i%2==0) sum=sum+i; } couta和b之间的偶数之和为sum=sumendl; //两数之间的奇数的平方和