第三章作业

习题5

#include<iostream>
using namespace std;
int main()
{
double e=1,f=1;
int i=0;
while(1/f>=
4000
10e-6)
{
i++;
f=f*i;
e=e+1/f;

}
cout<<"e的近似值="<<e<<endl;
return 0;
}

习题6

#include<iostream>
using namespace std;
int main()
{
double pi=1;
int i=1;
int f=1;
while(1.0/i>=10e-8)
{
f=-f;
i=i+2;
pi=pi+f*(1.0/i);

}
cout<<"圆周率的近似值="<<4*pi<<endl;
return 0;
}


习题7

#include<iostream>
using namespace std;
int main()
{
int number;
cout<<"请输入一个数:";
cin>>number;
if(number<10)
cout<<number<<"小于10";
else if(number<100)
cout<<number<<"在10到100之间";
else if(number<1000)
cout<<number<<"在100到1000之间";
else
cout<<number<<"大于1000"<<endl;

return 0;
}

习题8

#include<iostream>
using namespace std;
int main()
{
cout<<" *"<<endl;
cout<<" * * *"<<endl;
cout<<" * * * * * "<<endl;
cout<<"* * * * * * * "<<endl;
cout<<" * * * * * "<<endl;
cout<<" * * *"<<endl;
cout<<" *"<<endl;
return 0;

}

习题9

#include<iostream>
using namespace std;
int main()
{
int n=1,a=0;
while(a<=1000)
{
a=a+n*n;
n=n+1;
}
cout<<"满足最大值n="<<n<<endl;
return 0;

}

2.编程求“百钱百鸡”问题。（鸡翁一值钱五，鸡母 一值钱三，鸡雏三值钱一。百钱买百鸡，问鸡翁、鸡母、鸡雏各几何？
#include<iostream>
#include<iomanip>
using namespace std;

int main()
{
int i,j,k;
for(i=0;i<=20;i++)
for(j=0;j<=33;j++)
for(k=0;k<=300;k++)
if(5*i+3*j+k/3==100&&i+j+k==100)
cout<<"鸡公数量为:"<<i<<"个"<<setw(16)
<<"鸡母数量为:"<<j<<"个"<<setw(16)
<<"鸡雏数量为:"<<k<<"个"<<endl;

return 0;
}