Compilare: user.cpp: In function ‘void read()’: user.cpp:18:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,x,y,d; ^ user.cpp: In function ‘void solve_2()’: user.cpp:151:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<ans.size();i++) ^ user.cpp: In function ‘void solve_1()’: user.cpp:102:23: warning: ‘c’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout<<l<<' '<<c<<' '<<ans<<'\n'; ^ user.cpp:102:15: warning: ‘l’ may be used uninitialized in this function [-Wmaybe-uninitialized] fout<<l<<' '<<c<<' '<<ans<<'\n'; ^