Tema nr28

#include <iostream>
#include <conio.h>

using namespace std;

int s(int n)
{
    if(n==0)
        return 0;
    else
    {
        if(n%2 == 0)
            return s(n-2)+n;
        else
            return s(n-1)+n;
    }
}

int main()
{
    int n;
    cin>>n;
    cout<<s(n);
}
//-----------------------------------------------------------------------------------------------------------------\\
#include <iostream>
#include <conio.h>

using namespace std;

int s1(int n)
{
    if(n<=0)
        return 0;
    else
        if(n%2 == 0)
            return s1(n-1)+n;
        else
            return s1(n-2)+n;
}

int main()
{
    int n;
    cin>>n;
    cout<<s1(n);
}
//------------------------------------------------------------------------------------------------------------------\\
#include <iostream>
#include <conio.h>

using namespace std;

int prim(int n,int i)
{
    if(i>n/2)
        return 1;
    else
        if (n%i==0)
            return 0;
        else
            return prim(n,i+1);
}

int main()
{
    int n;
    cin>>n;
    if(prim(n,2))
        cout<<"Prim";
    else
        cout<<"Nu este prim";
}
//----------------------------------------------------------------------------------------------------------------\\
#include <iostream>
#include <conio.h>

using namespace std;

int prim(int n,int i)
{
    if(i>n/2)
        return 1;
    else
        if (n%i==0)
            return 0;
        else
            return prim(n,i+1);
}

int main()
{
    int n, s = 0, i;
    cin>>n;
    for(i=2;i<n;i++)
        if(prim(i,2))
            s++;
    cout<<s;
}
//----------------------------------------------------------------------------------------------------------------\\