Compilare: user.cpp: In function ‘void calc(char)’: user.cpp:24:13: warning: unused variable ‘c’ [-Wunused-variable] int a,b,c; ^ user.cpp: In function ‘int solv()’: user.cpp:60:52: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!op.empty() && p[op.top()]>=p[s[i]]) ^ user.cpp:60:61: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(!op.empty() && p[op.top()]>=p[s[i]]) ^ user.cpp:34:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^ user.cpp: In function ‘int main()’: user.cpp:79:9: warning: unused variable ‘i’ [-Wunused-variable] int i,j; ^ user.cpp:79:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j; ^