C++作业4

（1）项目三：乘法口诀表

#include<iostream>using namespace std;int main(){int i,j;cout<<"九九乘法口诀表来啦"<<endl;for(i=1;i<=9;i++){for(j=1;j<=i;j++)cout<<j<<"*"<<i<<"="<<j*i<<"\t";cout<<endl;}return 0;}

(2)项目四：输出完数

#include<iostream>using namespace std;int main(){int i,j,k;cout<<"1000以内的所有完数有:";for(i=2;i<=1000;i++){k=0;for(j=1;j<=i/2;j++)if(i%j==0) k=k+j;if(k==i) cout<<k<<",";}cout<<endl;return 0;}

(3)项目六：输出星号图

#include<iostream>using namespace std;int main(){int i,j;for(j=1;j<=6;j++)cout<<" ";cout<<"*"<<endl;for(i=1;i<=5;i++){for(j=1;j<=6-i;j++)cout<<" ";cout<<"*";for(j=1;j<=-1+2*i;j++)cout<<" ";cout<<"*";cout<<endl;}for(j=1;j<=13;j++)cout<<"*";cout<<endl;return 0;}