2.8题#include<iostream>usingnamespacestd;intmain(){charc1='C',c2='h',c3='i',c4='n',c5='a';c1+=4;c2+=4;c3+=4;c4+=4;c5+=4;cout<<"passwordis:"<<c1<<c2<<c3<<c4<<c5<<endl;return0;}3.2题#include<iostream>#include<iomanip>usingnamespacestd;intmain(){floath,r,l,s,sq,vq,vz;constfloatpi=3.1415926;cout<<"pleaseenterr,h:";cin>>r>>h;l=2*pi*r;s=r*r*pi;sq=4*pi*r*r;vq=3.0/4.0*pi*r*r*r;vz=pi*r*r*h;cout<<setiosflags(ios::fixed)<<setiosflags(ios::right)<<setprecision(2);cout<<"l="<<setw(10)<<l<<endl;cout<<"s="<<setw(10)<<s<<endl;cout<<"sq="<<setw(10)<<sq<<endl;cout<<"vq="<<setw(10)<<vq<<endl;cout<<"vz="<<setw(10)<<vz<<endl;return0;}3.3题#include<iostream>usingnamespacestd;intmain(){floatc,f;cout<<"请输入一个华氏温度:";cin>>f;c=(5.0/9.0)*(f-32);//注意5和9要用实型表示,否则5/9值为0cout<<"摄氏温度为:"<<c<<endl;return0;}3.4题#include<iostream>usingnamespacestd;intmain(){charc1,c2;cout<<"请输入两个字符c1,c2:";c1=getchar();//将输入的第一个字符赋给c1c2=getchar();//将输入的第二个字符赋给c2cout<<"用putchar函数输出结果为:";putchar(c1);putchar(c2);cout<<endl;cout<<"用cout语句输出结果为:";cout<<c1<<c2<<endl;return0;}3.4题另一解#include<iostream>usingnamespacestd;intmain(){charc1,c2;cout<<"请输入两个字符c1,c2:";c1=getchar();//将输入的第一个字符赋给c1c2=getchar();//将输入的第二个字符赋给c2cout<<"用putchar函数输出结果为:";putchar(c1);putchar(44);putchar(c2);cout<<endl;cout<<"用cout语句输出结果为:";cout<<c1<<","<<c2<<endl;return0;}3.5题#include<iostream>usingnamespacestd;intmain(){charc1,c2;inti1,i2;//定义为整型cout<<"请输入两个整数i1,i2:";cin>>i1>>i2;c1=i1;c2=i2;cout<<"按字符输出结果为:"<<c1<<","<<c2<<endl;return0;}3.8题#include<iostream>usingnamespacestd;intmain(){inta=3,b=4,c=5,x,y;cout<<(a+b>c&&b==c)<<endl;cout<<(a||b+c&&b-c)<<endl;cout<<(!(a>b)&&!c||1)<<endl;cout<<(!(x=a)&&(y=b)&&0)<<endl;cout<<(!(a+b)+c-1&&b+c/2)<<endl;return0;}3.9题include<iostream>usingnamespacestd;intmain(){inta,b,c;cout<<"pleaseenterthreeintegernumbers:";cin>>a>>b>>c;if(a<b)if(b<c)cout<<"max="<<c;elsecout<<"max="<<b;elseif(a<c)cout<<"max="<<c;elsecout<<"max="<<a;