C++第四次作业

一、分数的累加

#include<iostream>using namespace std;int main(){double i(1),sum=0,k;while(i<21){k=i/(i+2);sum=k+sum;i=i+2;k=i/(i+2);sum=-k+sum;i=i+2;}cout<<"sum="<<sum<<endl;return 0;}

二、图形的输出

#include<iostream>using namespace std;void main(){int i,j;for(i=1;i<=6;i++)      {          for(j=0;j<=6-i;j++)              cout<<" ";          if(i>1)          {              cout<<"*";              for(j=1;j<2*(i-1);j++)                  if(i<6)                      cout<<" ";                  else                      cout<<"*";          }          cout<<"*\n";          }  }

三、三色球问题

#include<iostream>using namespace std;int main(){int i,j,k;for(i=0;i<=3;i++){for(j=0;j<=3;j++){k=8-i-j;if(k<=6)cout<<"红球"<<i<<"个"<<"白球"<<j<<"个"<<"黑球"<<k<<"个"<<endl;}}return 0;}