Compilare: user.cpp: In function ‘int lukeuler(int)’: user.cpp:26:28: warning: no return statement in function returning non-void [-Wreturn-type] c = c * (n - 1); } } ^ user.cpp: In function ‘int main()’: user.cpp:29:40: 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:30:42: 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:32:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &a, &n); ^