Compilare: user.cpp: In function ‘bool bktr()’: user.cpp:16:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod.size();++i) ^ user.cpp:23:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<stiva[1].size();++i) ^ user.cpp:30:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod.size();++i) ^ user.cpp:58:1: warning: no return statement in function returning non-void [-Wreturn-type] } ^ user.cpp: In function ‘int main()’: user.cpp:61:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("immortal.in","r",stdin); ^ user.cpp:62:39: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("immortal.out","w",stdout); ^ user.cpp:63:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d %d",&n,&m,&k); ^ user.cpp:77:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^