Compilare: user.cpp: In function ‘bool drum()’: user.cpp:27:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<v[nod].size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:62:11: warning: unused variable ‘ch’ [-Wunused-variable] char *ch,*p; ^ user.cpp:62:15: warning: unused variable ‘p’ [-Wunused-variable] char *ch,*p; ^ user.cpp:59:34: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("senat.in","r",stdin); ^ user.cpp:60:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("senat.out","w",stdout); ^ user.cpp:64:26: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d\n",&n,&m); ^ user.cpp:70:16: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(c); ^ /tmp/cc60kOOG.o: In function `main': user.cpp:(.text.startup+0xa2): warning: the `gets' function is dangerous and should not be used.