Compilare: main.cpp: In function 'int main()': main.cpp:167:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < ports.size(); ++i) { ~~^~~~~~~~~~~~~~ main.cpp:175:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ports.size(); ++i) { ~~^~~~~~~~~~~~~~ main.cpp:188:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ports.size(); ++i) { ~~^~~~~~~~~~~~~~ main.cpp:215:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 2; i < ports.size(); ++i) { ~~^~~~~~~~~~~~~~ main.cpp:223:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ports.size(); ++i) { ~~^~~~~~~~~~~~~~