inline
#include <stdlib.h> #include <stdio.h> int is_even(int n) { if (n < 0) n = -n; even: if (n == 0) return 1; n--; goto odd; odd: if (n == 0) return 0; n--; goto even; } int main(int argc, char **argv) { if (argc != 2 ) { fprintf(stdout, "Usage: %s <n>\n", argv[0]); exit(EXIT_FAILURE); } else { int n = atoi(argv[1]); puts(is_even(n) ? "true" : "false"); } return 0; }