Compilare: user.cpp: In function ‘void antibfs(trie*)’: user.cpp:57:51: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (unsigned int j=0;j<min(fr->y.size(),1);j++) sol[fr->y[j]]=fr->x; ^ user.cpp: In function ‘int main()’: user.cpp:61:29: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.in","r",stdin); ^ user.cpp:62:31: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("abc2.out","w",stdout); ^ user.cpp:63:10: warning: ignoring return value of ‘char* gets(char*)’, declared with attribute warn_unused_result [-Wunused-result] gets(s+1); n=0; root=new trie; ^ /tmp/ccw1bn8S.o: In function `main': user.cpp:(.text.startup+0x56): warning: the `gets' function is dangerous and should not be used.