Compilare: user.cpp: In function ‘int phi(int)’: user.cpp:9:9: warning: variable ‘lim’ set but not used [-Wunused-but-set-variable] int lim=(int)sqrt((double)n); ^ user.cpp: In function ‘int main()’: user.cpp:49:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.in", "r", stdin); ^ user.cpp:50:46: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("inversmodular.out", "w", stdout); ^ user.cpp:52:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d", &a, &n); ^