Compilare: user.cpp:1:9: warning: #pragma once in main file #pragma once ^~~~ user.cpp: In function ‘void step(int)’: user.cpp:61:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (i + 1 < indexes.size()) { ~~~~~~^~~~~~~~~~~~~~~~ user.cpp: In function ‘int main()’: user.cpp:106:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < elem.size(); ++i) { ~~^~~~~~~~~~~~~ user.cpp:111:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < indexes.size(); i++) ~~^~~~~~~~~~~~~~~~