c++作业4

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

#include<iostream>
using namespace std;
int main()
{
int x,y,z;
cout<<"     *"<<endl;
for(x=1;x<=4;x++)
{
for(y=4;(y-x)>=0;y--)
cout<<" ";
cout<<"*";
for(z=1;z<=(2*x-1);z++)
cout<<" ";
cout<<"*"<<endl;
}
cout<<"***********"<<endl;
return 0;
}

#include<iostream>
using namespace std;
int main()
{
int i=0,s=0;
double x=0.01,y=0;
cout<<"陌生人累计得到富翁的的钱"<<"\t"<<"富翁累计得到陌生人的钱"<<endl;
while(i<=29)
{
y=x+y;
x=x*2.0;
s=s+100000;
i++;
cout<<"第"<<i<<"天"<<"\t"<<y<<"元                "<<"\t"<<s<<"元"<<endl;
}
if(y>s)   cout<<"陌生人赚了"<<endl;
if(y<s)   cout<<"陌生人亏了"<<endl;
return 0;
}