Collatz Conjecture with Corutines in C (alliterative!)

collatz.c

#include <stdio.h>
#include <setjmp.h>

void even(int);
void odd(int);

int main(int argc, char *argv[]) {
    even(7);
    return 0;
}

jmp_buf even_task, odd_task;

void even(int n) {
    int aux;
    if (!(aux = setjmp(even_task))) {
        odd(n);
    } else {
        n = aux;
    }
    while (n > 1) {
        while (n % 2 == 0) {
            printf("Even! %3d / 2 =\n", n);
            n /= 2;
        }
        if (!(aux = setjmp(even_task))) {
            longjmp(odd_task, n);
        } else {
            n = aux;
        }
    }
    printf("Done!   1\n");
}

void odd(int n) {
    while (n > 1) {
        if (n % 2 == 1) {
            printf("Odd!  %3d * 3 + 1 =\n", n);
            n = 3 * n + 1;
        }
        int aux;
        if (!(aux = setjmp(odd_task))) {
            longjmp(even_task, n);
        } else {
            n = aux;
        }
    }
}

output.txt

Odd!    7 * 3 + 1 =
Even!  22 / 2 =
Odd!   11 * 3 + 1 =
Even!  34 / 2 =
Odd!   17 * 3 + 1 =
Even!  52 / 2 =
Even!  26 / 2 =
Odd!   13 * 3 + 1 =
Even!  40 / 2 =
Even!  20 / 2 =
Even!  10 / 2 =
Odd!    5 * 3 + 1 =
Even!  16 / 2 =
Even!   8 / 2 =
Even!   4 / 2 =
Even!   2 / 2 =
Done!   1