Compilare: user.cpp: In function ‘void bktr(int)’: user.cpp:15:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod.size();++i) ^ user.cpp:22:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<stiva[1].size();++i) ^ user.cpp:29:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<nod.size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:60:37: 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:61:39: 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:62:31: 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:76:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d",&x,&y); ^