c++第四次实验

项目1利用循环求和

while语句

#include <iostream>using namespace std;int main(){int i(0),sum(0);while(i<=1000){sum=sum+i;i=i+2;}cout<<"sum="<<sum<<endl;}

do-while语句

#include <iostream>using namespace std;int main(){int i(0),sum(0);do{sum=sum+i;i=i+2;}while(i<=1000);cout<<"sum="<<sum<<endl;}

for语句

#include <iostream>using namespace std;int main(){int i,sum(0);for(i=0;i<=1000;i=i+2){sum=sum+i;}cout<<"sum="<<sum<<endl;}

项目4输出完数

#include <iostream>using namespace std;int main(){int i(0),s(1),sum(0),n(0);for(i=1;i<=1000;i++){sum=0;for(s=1;s<=i/2;s++){if(i%s==0) sum=sum+s; }if(sum==i) {n=n+1;cout<<i<<"是1000以内的第"<<n<<"个完数"<<endl; }}return 0;}