#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>


int randomNumber(void) //Returns a random number (use time as seed) on range [0 - 1000]
{
    srand(time(NULL)); //using time as seed
    int random = rand() % 1000; //%1000 limits random number to be between 0 and 1000

    return random; //returning random number
}

int sumOfOdd(int random) //Returns the sum of odd numbers between 0 and the random number
{
    int ranNum = random; //getting random number from randomNumber
    int sumCalc;
    int sum;
    if (ranNum % 2) //checking if it is odd or not for calculation purposes
    {
        sumCalc = (ranNum + 1) / 2; //if number is odd add +1
    }
    else
    {
        sumCalc = ranNum / 2;
    }

    sum = pow(sumCalc, 2); //calculating sum of odd with formula (n)^2
    return sum;
}

int isTetranacci(int sum)
{
    int sumTetra = sum;

    if ((sumTetra == 0 || sumTetra == 1 || sumTetra == 2 || sumTetra == 4 || sumTetra == 8 || sumTetra == 15 || sumTetra == 56 || sumTetra == 108 || sumTetra == 208 || sumTetra == 401 || sumTetra == 773 || sumTetra == 1490 || sumTetra == 2872 || sumTetra == 5536 || sumTetra == 10671 || sumTetra == 20569 || sumTetra == 39648 || sumTetra == 76424 || sumTetra == 147312 )) //checks if number is tetranacci number
    {
        printf("Number %d is Tetranacci\n", sumTetra);
    }
    else
    {
        printf("Number %d is not Tetranacci\n", sumTetra);
    }
    return 0;
}



int main(void)
{
    int random = randomNumber();
    printf("Random number: %d\n", random);

    int sum = sumOfOdd(random);
    printf("Sum of odd numbers: %d\n", sum);

    isTetranacci(sum);

    return 0;
}