Compilare: user.cpp: In function ‘int main()’: user.cpp:192: warning: unused variable ‘w’ user.cpp:198: warning: unused variable ‘dfs_time’ user.cpp:185: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:186: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:188: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:194: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result