Compilare: user.cpp: In function ‘void eval()’: user.cpp:21:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (1-t[c]==0) ns.push('a'); else ns.push('b'); ^ user.cpp:31:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (t[c]==0 || t[c1]==0) ns.push('a'); else ns.push('b'); ^ user.cpp:31:40: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (t[c]==0 || t[c1]==0) ns.push('a'); else ns.push('b'); ^ user.cpp:35:28: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (t[c]==1 || t[c1]==1) ns.push('b'); else ns.push('a'); ^ user.cpp:35:40: warning: array subscript has type ‘char’ [-Wchar-subscripts] if (t[c]==1 || t[c1]==1) ns.push('b'); else ns.push('a'); ^ user.cpp:39:21: warning: array subscript has type ‘char’ [-Wchar-subscripts] fout<<t[ns.top()]; ^ user.cpp: In function ‘int main()’: user.cpp:112:12: warning: array subscript has type ‘char’ [-Wchar-subscripts] t[c]=1-t[c]; ^ user.cpp:112:19: warning: array subscript has type ‘char’ [-Wchar-subscripts] t[c]=1-t[c]; ^