Compilare: user.cpp: In function ‘bool BF()’: user.cpp:44:57: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<list[act.first][act.second].size();i++){ ^ user.cpp:56:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(long i=0;i<list[D][D].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:96:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<E.size();i++){ ^ user.cpp:80:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algola.in","r",stdin); ^ user.cpp:81:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("algola.out","w",stdout); ^ user.cpp:83:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%ld %ld",&n,&m); ^ user.cpp:86:44: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=1;i<=n;i++) {scanf("%ld",&hum[i]); sum+=hum[i];} ^ user.cpp:89:66: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] for(i=0;i<m;i++) scanf("%ld %ld %ld",&E[i].x,&E[i].y,&E[i].c); ^