Compilare: main.cpp: In function 'int main()': main.cpp:82:66: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = tbc.size() / 2 - 1, j = tbc.size() / 2; i >= 0 || j < tbc.size(); --i, ++j) ~~^~~~~~~~~~~~ main.cpp:86:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(j < tbc.size()) ~~^~~~~~~~~~~~