Compilare: user.cpp: In function ‘void solve()’: user.cpp:81:39: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(c[first->state][first->last] < first->cost){ ^ user.cpp:86:61: warning: array subscript has type ‘char’ [-Wchar-subscripts] if(!(first -> state & (1 << i)) && a[first->last][i]){ ^ user.cpp:88:58: warning: array subscript has type ‘char’ [-Wchar-subscripts] int newcost = first->cost + a[first->last][i]; ^