Compilare: main.cpp: In function 'int main()': main.cpp:57:12: warning: variable 'prevW' set but not used [-Wunused-but-set-variable] double prevW = 0; ^~~~~ main.cpp:25:36: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hallway.in","r",stdin); ^ main.cpp:26:38: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result] freopen("hallway.out","w",stdout); ^