Compilare: user.cpp: In function ‘int main()’: user.cpp:10:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("laundering.in", "rt", stdin); ^ user.cpp:11:41: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("laundering.out", "wt", stdout); ^ user.cpp:43:10: warning: ‘chr’ may be used uninitialized in this function [-Wmaybe-uninitialized] char chr; ^~~