rec

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

int tailrec_cover(int x)
{
    return tailrec_fact(x,1); //apeleaza tailrec_fact cu nr =1
}
int tailrec_fact(int x, int nr)
{
    if(x==0) return nr;
    return tailrec_fact(x-1,x*nr);
}

int non_tailrec_fact(int x)
{
    if(x==0) return 1;
    return x*non_tailrec_fact(x-1);
}

int directrec_fact(int x)
{
    if(x==0)
        return 1;
    else
        return x*directrec_fact(x-1);
}

int decr(int a)
{
    return a-1;
}

int indirectrec_fact1(int x)
{
    if(x==0)
        return 1;
    else
        return x*indirectrec_fact2(x-1);
}

int indirectrec_fact2(int x)
{
    if(x==0)
        return 1;
    else
        return x*indirectrec_fact1(x-1);
}
int x;
int main()
{
    printf("x= ");
    scanf("%d", &x);
    printf("Tail-recursive function: %d\n", tailrec_cover(x));
    printf("Non-tail-recursive function: %d\n", non_tailrec_fact(x));
    printf("Direct recursive function: %d\n", directrec_fact(x));
    printf("Indirect recursive function: %d\n", indirectrec_fact1(5));
    return 0;
}