//1/(2*3)+2/(3*4)+...(n/((n+1)(n+2))#include<iostream.h>#include<conio.h> float e(int k){return (float)k/((k+1)*(k+2));} float s(int k){if(k==1) return (float)1/(2*3);else return e(k)+s(k-1);} void main(){int n;cout<<"n=";cin>>n;cout<<s(n)<<endl;getch();} {module orizontal600}
//1+1/2+...1/n#include<iostream.h>#include<conio.h> float e(int k){if (k==1) return 1;else return (float)1/k+e(k-1);} void main(){int n;cout<<"n=";cin>>n;cout<<e(n)<<endl;getch();} {module orizontal600}
//1*2+2*3+..+n*(n+1)#include<iostream.h>#include<conio.h> int p(int k){return k*(k+1);} int s(int k){if (k==0) return 0;else return p(k)+s(k-1);} void main(){int n;cout<<"n=";cin>>n;cout<<s(n)<<endl;getch();} {module orizontal600}
//combinari#include<iostream.h>#include<conio.h> long comb(int n,int k){if (k==0) return 1;else if (k>n) return 0; else return (comb(n-1,k)+comb(n-1,k-1));} void main(){int k,n;cout<<"n=";cin>>n;cout<<"k=";cin>>k;cout<<//"combinari de"<<n<<"elemente luate cate"<<k<<":"<<comb(n,k)<<endl;getch();} {module orizontal600}
//sa se calculeze suma componentelor unui vector cu n elemente#include<iostream.h>#include<conio.h>typedef int vector[20];int n;vector v; int suma(vector v,int n){if (n==0) return 0;else return (v[n]+suma(v,n-1));} void main(){int i;cout<<"n=";cin>>n;for(i=1;i<=n;i++) {cout<<"v["<<i<<"]=";cin>>v[i];}cout<<"suma este"<<suma(v,n)<<endl;getch();} {module orizontal600}