Compilare: user.cpp: In function ‘bool bfs()’: user.cpp:24: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void max_flow()’: user.cpp:43: warning: comparison between signed and unsigned integer expressions user.cpp:39: warning: unused variable ‘step’ user.cpp: In function ‘int main()’: user.cpp:66: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:67: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:68: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:72: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result