C++作业（四）

<span style="font-family: Arial, Helvetica, sans-serif; background-color: rgb(255, 255, 255);">项目一：分数的累加</span>

#include<iostream.h>void main(){int x,y,sun;for(x=1;x<=19;x=x+2){sum=sum+x/(x+2)*y;y=-y;}}

项目二：乘法表

#include<iostream.h>void main(){int x,y,z;for(x=1;x<=9;x++){for(y=1;y<=9;y++)z=x*y;cout<<x<<"*"<<y<<"="<<endl;}}

项目三：星号图

</pre><p><pre name="code" class="cpp">#include<iostream.h>void main(){      int a,b,c,d,e;      for(d=1; d<=5; d++)          cout<<" ";      cout<<"*"<<endl;      for(a=1; a<=4; a++)      {          for(b=1; b<=(5-a); b++)              cout<<" ";          cout<<"*";          for(c=1; c<=(2*a-1); c++)              cout<<" ";          cout<<"*"<<endl;      }  for(e=1; e<=11; e++)          cout<<"*";}