Compilare: user.cpp: In function ‘long long int sol(int)’: user.cpp:13:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<r[i].size();j++){ ^ user.cpp:23:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<r[0].size();i++) ^ user.cpp:10:16: warning: unused variable ‘s’ [-Wunused-variable] long long nr=0,s=0;int st; ^ user.cpp:10:24: warning: unused variable ‘st’ [-Wunused-variable] long long nr=0,s=0;int st; ^