C++作业4

#include<iostream>
using namespace std;
int main()
{
int k=1;
double i=1,j,sum=0;
while(i<=10)
{
j=(i*2-1)/(i*2+1);
sum=sum+k*j;
k=-k;
i++;
}
cout<<sum;
cout<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
int g,h,i,j,k,l,m;
for(g=0;g<5;g++)
cout<<" ";
cout<<"*";
cout<<endl;
for(i=0;i<4;i++)
{
for(j=0;j<4-i;j++)
cout<<" ";
cout<<"*";
for(k=0;k<=2*i;k++)
cout<<" ";
cout<<"*";
cout<<endl;
}
for(m=0;m<=10;m++)
cout<<"*";
cout<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
int a=1;
double x,y,z;
for(x=0;x<=20;x++)
for(y=0;y<=33;y++)
for(z=0;z<=300;z++)
if(5*x+3*y+z/3==100 && x+y+z==100)
cout<<a++<<":鸡翁"<<x<<"只,鸡母"<<y<<"只,鸡雏"<<z<<"只\n";
return 0;
}