Compilare: user.cpp: In function ‘int main()’: user.cpp:22:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i*i<=b;i++) ^ user.cpp:27:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(i*i!=b) ^ user.cpp:33:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1;i<=n;i++) ^ user.cpp:34:24: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=i;j<=n;j++) ^ user.cpp:47:23: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(!mp[a]) ^