Рекурсія

# include <iostream>

using namespace std;

int main ()
{
	setlocale(LC_ALL, "Ukrainian");
	int mas[5]={2,3,0,4,8};
	int s=0;
	for (int i=0; i<5; i++)
		s=s+mas[i];
	cout <<"Suma="<< s << "\n";

	system ("pause"); 
        return 0;
}

# include <iostream>

using namespace std;

int suma(int a[], int counter)
{
 if (counter == 1)
  return a[0];
 else
 {
  return a[0] + suma(a+1,counter-1);
 }
}

int main ()
{
	setlocale(LC_ALL, "Ukrainian");
	int mas[5]={2,3,0,4,8};
	cout <<"Suma="<< suma(mas,5) << "\n";
	system ("pause"); 
    return 0;
}

# include <iostream>

using namespace std;

int main ()
{
	setlocale(LC_ALL, "Ukrainian");
	int fibo[100];
	fibo[0]=1;
	fibo[1]=1;
	int n;
	cin >> n;
	for (int i=2; i<n; i++)
	{
		fibo[i]=fibo[i-1]+fibo[i-2];
	}
	cout <<fibo[n-1]<< "\n";
	system ("pause"); 
    return 0;
}

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

int main ()
{
int n;
cin>>n;
cout<<"Число Фібоначі = "<<fib(n);
}

Розв'язок задачі