Compilare: user.c: In function ‘edge’: user.c:15:1: warning: control reaches end of non-void function [-Wreturn-type] } ^ user.c: In function ‘main’: user.c:49:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.in", "r", stdin); ^ user.c:50:12: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen("puzzle2.out", "w", stdout); ^ user.c:53:10: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i", &n, &m); ^ user.c:58:14: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf("%i%i", &x, &y); ^