Compilare: user.cpp: In function ‘int verif(int)’: user.cpp:136: warning: comparison between signed and unsigned integer expressions user.cpp:147: warning: comparison between signed and unsigned integer expressions user.cpp:163: warning: comparison between signed and unsigned integer expressions user.cpp:169: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘void sortare_topologica()’: user.cpp:200: warning: comparison between signed and unsigned integer expressions user.cpp: In function ‘int main()’: user.cpp:211: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:212: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result user.cpp:213: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result user.cpp:217: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result