Compilare: user.cpp: In function ‘void back()’: user.cpp:30:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<imms.size();++i) ^ user.cpp: In function ‘int main()’: user.cpp:79:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<=ras.size()-2;i+=2) ^ user.cpp:67:37: 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:68:39: 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:69:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&m,&nem); ^ user.cpp:74:34: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&im.x,&im.y); ^