C++作业4

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

#include <iostream>
using namespace std;
int main()
{
long i,m1,n2=0,x=1,m2;
m1=100000*30;
cout<<"30天陌生人给富翁的钱数："<<m1<<endl;
for(i=1;i<30;i++)
{
x=x*2;
n2=n2+x;
m2=n2/100;
}
cout<<"富豪应给陌生人"<<m2<<"元"<<endl;
if(m1>m2)
cout<<"陌生人亏了"<<endl;
else
cout<<"富豪亏了"<<endl;
return 0;
}

#include <iostream>
using namespace std;
int main()
{
int r,w,b;
cout<<"任意取出8个小球其颜色的方案有："<<endl;
for(r=0;r<=3;r++)
for(w=0;w<=3;w++)
{
b=8-r-w;
if(b>=0&&b<=6)
{
cout<<"红色："<<r<<"个"<<"  "<<"白色："<<w<<"个"<<"  "<<"黑色："<<b<<"个"<<endl;

}
}
return 0;
}