第四周作业

第一大题

3

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

5

#include<iostream>using namespace std;int main(){double b=1,c=1,g=1;int a,d=1;while(!(b<1e-6))    {for(a=1;a<=d;a++)c*=a;b=1/c;g+=b;c=1;d++;    }    cout<<"e="<<g<<endl;       return 0;}

6

#include<iostream>using namespace std;int main(){double a=1,b=1,c,d,f=1,pai;do{        a+=2;b*=-1;c=1.0/a;d=b*c;f+=d;}while(c>1e-6);pai=4*f;cout<<pai<<endl;return 0;}

7

#include<iostream>using namespace std;int main(){int z;cout<<"请输入一数值:";cin>>z;if (z<=10) cout<<z<<"is-∞to10";else if (z>10&&z<=100) cout<<z<<"is10to100";  else if (z>100&&z<=1000) cout<<z<<"is100to1000";  else cout<<z<<"is1000to+∞";  cout<<z<<endl;    return 0;}

8

#include<iostream>#include<iomanip>using namespace std;int main(){cout<<setw(7)<<"*"<<endl;  cout<<setw(9)<<"* * *"<<endl;cout<<setw(11)<< "* * * * *" <<endl;cout<<setw(13)<<"* * * * * * *"<<endl;      cout<<setw(11)<<"* * * * *"<<endl;      cout<<setw(9)<<"* * *"<<endl;      cout<<setw(7)<<"*"<<endl;    return 0; }

9

#include<iostream>using namespace std;int main(){int sum=0,n;for(n=1;;n++){sum=sum+n*n;if (sum>=1000)break;}cout<<"满足\"1*1+2*2+3*3+...+n*n<=1000\"d最大n值为"<<n-1<<endl; return 0;}

10

#include<iostream>using namespace std;int main(){double sum1=0,sum2,n,m=1;for(n=0.01;m<=30;){sum1+=n;n=n*2;        m++;}sum2=100000*30;cout<<"百万富翁给穷人的钱为:"<<sum1<<endl<<"穷人给百万富翁的钱为:"<<sum2<<endl;return 0;}

11

#include<iostream>using namespace std;int main(){int i,j,sum;for (i=1;i<=9;i++){for (j=1;j<=i;j++){sum=i*j;cout<<j<<"*"<<i<<"="<<sum<<"\t";}cout<<endl;}return 0;}