Compilare: user.cpp: In function ‘int main()’: user.cpp:49:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < v.size() ; i++) ^ user.cpp:50:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = 0 ; j < v.size() ; j++) ^ user.cpp:51:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k = 0 ; k < v.size() ; k++) ^ user.cpp:62:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0 ; i < s.size() ; i++) ^ user.cpp:39:33: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto.in","r",stdin); ^ user.cpp:40:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto.out","w",stdout); ^ user.cpp:42:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d%d",&n,&S); ^ user.cpp:45:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d",&x); ^