Compilare: user.cpp: In function ‘void write(int, int)’: user.cpp:59:13: warning: unused variable ‘aux_x’ [-Wunused-variable] int aux_x = x; ^ user.cpp:65:67: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < s[wr[i]].size() - a[wr[i]][wr[i-1]]; j++) ^ user.cpp:68:47: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < s[wr[i]].size(); ++j) ^