Compilare: user.c: In function ‘power0’: user.c:30:9: warning: implicit declaration of function ‘power’ [-Wimplicit-function-declaration] return a * power (a * a, b / 2); ^ user.c: In function ‘main’: user.c:75:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen (IN, "r", stdin); ^ user.c:76:13: warning: ignoring return value of ‘freopen’, declared with attribute warn_unused_result [-Wunused-result] freopen (OUT, "w", stdout); ^ user.c:82:11: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%d", &t); ^ user.c:85:15: warning: ignoring return value of ‘scanf’, declared with attribute warn_unused_result [-Wunused-result] scanf ("%lld", &nr); ^