Compilare: user.cpp: In function ‘int main()’: user.cpp:47:56: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(k1>0&&pr[s[i]]<=pr[op[k1]]){ ^ user.cpp:47:68: warning: array subscript has type ‘char’ [-Wchar-subscripts] while(k1>0&&pr[s[i]]<=pr[op[k1]]){ ^ user.cpp: In function ‘int calcul(int, int, char)’: user.cpp:16:1: warning: control reaches end of non-void function [-Wreturn-type] } ^