Compilare: user.cpp: In function ‘bool verif(std::string)’: user.cpp:14:11: warning: unused variable ‘i’ [-Wunused-variable] int k,i,m; ^ user.cpp: In function ‘void calc(int, int)’: user.cpp:27:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0;j<f[k][i].f.length();j++) ^ user.cpp:24:9: warning: unused variable ‘k1’ [-Wunused-variable] int k1,i1,j,ct,j1,j2; ^ user.cpp:24:12: warning: unused variable ‘i1’ [-Wunused-variable] int k1,i1,j,ct,j1,j2; ^