每日總結33
阿新 • • 發佈:2021-10-23
1.題目描述
#include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> #include<cmath> using namespace std; int main(){ for(int i=3;i<=400;i++){ int s=0; for(int j=1;j<i;j++){ if(!(i%j)) s+=j; } int t=0;for(int j=1;j<s;j++){ if(!(s%j)) t+=j; } if(s==t) cout<<i<<" "<<s<<endl; } return 0; }
2.題目描述
#include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> #include<cmath> using namespace std;int main(){ double n=1.0,m=2.0,k,ans=0.0; int s; cin>>s; for(int i=1;i<=s;i++){ ans+=double(m/n); k=n+m; n=m; m=k; } cout<<ans<<endl; return 0; }
3.題目描述
#include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> #include<cmath> using namespace std; int main(){ double x,t=0.0,s=0.0,u=1.0,d=1.0,c=1.0; cin>>x; while(fabs(u/d)>1e-6){ s+=c*(u/d); c=-c; t++,d*=t,t++,d*=t; u*=(x*x); } printf("%.6lf\n",s); return 0; }
4.題目描述
#include<iostream> #include<cstdlib> #include<cstdio> #include<cstring> #include<cmath> using namespace std; int main(){ double L=0.0,R=1.57089; while(1){ double mid=(L+R)/2.0; if(double(fabs(cos(mid/2.0)-sin(mid)))<1e-6){ printf("%.6lf\n",mid); break; } else if((cos(mid/2)-sin(mid))>0) L=mid; else R=mid; } return 0; }