Compilare: user.cpp: In function ‘int nrdiv(int)’: user.cpp:21:19: warning: left operand of comma operator has no effect [-Wunused-value] for(int i=0; i<np, prim[i]*prim[i]<=x; i++) ^ user.cpp: In function ‘int main()’: user.cpp:37:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxd.in", "r", stdin); ^ user.cpp:38:37: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("maxd.out", "w", stdout); ^ user.cpp:40:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d %d", &x, &y); ^