Compilare: user.cpp: In function ‘int main()’: user.cpp:23:35: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0; k<lines.size(); k++) ^ user.cpp:8:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("referat.in","r",stdin); ^ user.cpp:9:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("referat.out","w",stdout); ^ user.cpp:11:29: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d%d",&n,&l,&t); ^ user.cpp:15:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^ user.cpp:22:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^