Fibonacci

#include <stdio.h>

int fib( int n );
int fib_sum( int Start, int End );
int is_fib_sum( int n );

int main( void )
{
        printf("podaj liczbe\n");
        int n;
        scanf("%d",&n);

        if(is_fib_sum(n) == 1)
        {
            printf("%d jest suma conajwyzej 4 liczb fib", n);
        }
        else
        {
            printf("%d nie jest suma conajwyzej 4 liczb fibonacciego.",n);
        }

        return 0;
}
int fib( int n )
{
        if(n == 0)
        {
                return 0;
        }
        else if(n == 1)
        {
                return 1;
        }
        else
        {
                int fprim = 0;
                int f = 1;

                int m;

                for(int i = 2; i <= n; i++)
                {
                        m = f + fprim;
                        fprim = f;
                        f = m;
                }
                return f;
        }
}
int fib_sum( int iStart, int iEnd )
{
        int sum = 0;
        for(int i = iStart; i <= iEnd; i++)
        {
                sum += fib(i);
        }
        return sum;
}
int is_fib_sum( int n )
{
    if(n == 0) return 1;

    int currentIndex = 0;

    while(fib(currentIndex) < n)
    {
        int currentSum = 0;
        for(int i = currentIndex; i <= currentIndex + 3; i++)
        {
                currentSum = fib_sum(currentIndex,currentIndex + i);

               // printf("Porownanie: sumy=%d \t oraz liczby n=%d\n",currentSum,n);
                if(n == currentSum)
                {
                    return 1;
                }
        }
        currentIndex++;
    }
    currentIndex = 0;

    while(fib(currentIndex) < n)
    {

        int currentSum = 0;
        for(int i = currentIndex + 3; i > currentIndex; i--)
        {
                currentSum = fib_sum(i,currentIndex + 3);

                //printf("Porownanie: sumy=%d \t oraz liczby n=%d\n",currentSum,n);
                if(n == currentSum)
                {
                    return 1;
                }
        }
        currentIndex++;
    }
    return 0;
}