Compilare: user.cpp: In function ‘bool bellmanford(int)’: user.cpp:53:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < G[nod].size() ; ++i ) ^ user.cpp: In function ‘void citire()’: user.cpp:34:42: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.in" , "r" , stdin ); ^ user.cpp:35:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d" , &N ,&M ); ^ user.cpp:37:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d" , &x , &y , &c ); ^ user.cpp: In function ‘void tipar()’: user.cpp:66:44: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("bellmanford.out" , "w" , stdout ); ^