Compilare: user.cpp: In function ‘void prim()’: user.cpp:66:7: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(a>1) ^ user.cpp: In function ‘int main()’: user.cpp:74:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv.in","r",stdin); ^ user.cpp:75:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("sumdiv.out","w",stdout); ^ user.cpp:76:31: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%lld %lld", &a, &b); ^