Compilare: main.cpp: In function 'void push(int)': main.cpp:41:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 41 | for(int z=0;z<up.size();z++){ | ~^~~~~~~~~~ main.cpp:40:13: warning: unused variable 'i' [-Wunused-variable] 40 | int i=0,j=down.size()-1; | ^ main.cpp: In function 'void pop()': main.cpp:66:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 66 | for(int z=0;z<down.size();z++){ | ~^~~~~~~~~~~~ main.cpp:65:13: warning: unused variable 'i' [-Wunused-variable] 65 | int i=0,j=up.size()-1; | ^