day3

//zad1//
int isPrime(int n)
    {
        if (n == 2 || n == 3 || n == 5 || n == 7)
        {
            return 1;
        }
        if (n % 2 == 0 || n % 3 == 0 || n % 5 == 0 || n % 7 == 0)
        {
            return 0;
        }
        return 1;
    }
    int main()
    {

        printf("%s\n", isPrime(15) ? "Yes" : "No");


    return 0;
    }
---------------------------------------------------
//zad2//
void Eratosten(int n){

    int numbers[n];
    numbers[0] = 1;
    numbers[1] = 1;

    int start = 2;

    while(start <= 7){
        if(numbers[start] == 1){
            start++;
            continue;
        }

        numbers[start] = 0;

        for(int i = start * 2; i <= n; i += start){
            numbers[i] = 1;
        }

        start++;
    }

    for(int i = 0; i < n; i++){
        if(numbers[i] == 0){
            printf("%d\n", i);
        }
    }
}
int main ()
{
Eratosthen(100);
return 0;
}

-----------------------------------------
//zad3//
void BubbleSort(int arr[], int n){

    int temp;

    for(int i = 0 ; i < n - 1; i++){
      for(int j = 0 ; j < n - i - 1; j++){
        if(arr[j] > arr[j+1]){
         temp = arr[j];
         arr[j] = arr[j+1];
         arr[j+1] = temp;
       }
     }
   }
}
int main ()
{
int arr[] = {5, 12, 3, 21, 43};
    BubbleSort(arr, 5);
    for(int i = 0; i < 5; i++){
        printf("%d\n", arr[i]);
    }
return 0;
}

---------------------------------------------
//zad4//
int factorial(int n){
    if (n == 0){
        return 1;
    }
    return factorial(n - 1) * n;
}
int main ()
{
printf("%d\n", factorial(7));
return 0;
}
--------------------------------------------
//zad5//
int Fibonachi(int* arr, int n, int start){
    arr[0] = 0;
    arr[1] = 1;

    arr[start] = arr[start - 1] + arr[start - 2];

    if(start <= n){
        Fibonachi(arr, n, start + 1);
    }

    return arr[n - 1];
}
int main ()
{
int n = 8;
    int arr[n];
    printf("%d\n", Fibonachi(arr, n, 2));
return 0;
}
-------------------------------------------
//zad6//
int power(int n1, int n2);

int power(int a, int b) {
    if (b != 0){
        return (a * power(a, b - 1));
    }else{
        return 1;
    }
}
int main ()
{
int a, b, result;

    printf("Enter number: ");
    scanf("%d", &a);

    printf("Enter power: ");
    scanf("%d", &b);

    result = power(a, b);

    printf("%d", result);
return 0;

}
------------------------------------------
//zadd8//
double sumArr(double* arr, int size, int start){
    if (start == size){
        return 0;
    }
    return arr[start] + sumArr(arr, size, start + 1);
}
int main()
{
 double arr[] = {1, 6, 12, 16, 3, 5};
    printf("%f\n", sumArr(arr, 6, 0));
return 0;
}