Compilare: main.cpp: In function 'int main()': main.cpp:103:29: warning: unused variable 'del' [-Wunused-variable] char instructiune[100], del[3] = "()", *p,*z; ^~~ main.cpp:104:9: warning: unused variable 'i' [-Wunused-variable] int i, el; ^ main.cpp: In member function 'int Stack::extrage()': main.cpp:58:1: warning: control reaches end of non-void function [-Wreturn-type] } ^