Compilare: user.cpp: In function ‘int main()’: user.cpp:51:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(k=0;k<nrprim.size()&&ch[nrprim[k]];k++); ^ user.cpp:25:36: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto2.in", "r", stdin); ^ user.cpp:26:38: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("loto2.out", "w", stdout); ^ user.cpp:30:20: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ^ user.cpp:45:25: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &nr); ^