Compilare: user.cpp: In function ‘void prim(ll)’: user.cpp:16:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=4; i<=n; i+=2) ^ user.cpp:18:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=3; i<=n; i+=2) ^ user.cpp:21:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=2; j*i<=n; ++j) ^ user.cpp: In function ‘void fact(ll)’: user.cpp:31:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=3; i<=n; i+=2) ^ user.cpp: In function ‘int main()’: user.cpp:60:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=1; i<=t;++i) ^ user.cpp:71:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=3; i*i<=n;i+=2) ^ user.cpp:83:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=3; i*i<=n; i+=2) ^ user.cpp: In function ‘ll exp(int, int)’: user.cpp:12:1: warning: control reaches end of non-void function [-Wreturn-type] } ^