Compilare: main.cpp: In function 'int main()': main.cpp:57:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < vec_ab.size(); ++i) ~~^~~~~~~~~~~~~~~ main.cpp:62:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < vec_a.size(); ++i) ~~^~~~~~~~~~~~~~ main.cpp:67:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < vec_b.size(); ++i) ~~^~~~~~~~~~~~~~ main.cpp:72:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < vec_i.size(); ++i) ~~^~~~~~~~~~~~~~ main.cpp:112:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (have_to_take_friends_a > vec_a.size()) ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ main.cpp:115:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (have_to_take_friends_b > vec_b.size()) ~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~ main.cpp:130:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int idx_a = have_to_take_friends_a; idx_a < vec_a.size(); ++idx_a) ~~~~~~^~~~~~~~~~~~~~ main.cpp:132:52: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int idx_b = have_to_take_friends_b; idx_b < vec_b.size(); ++idx_b) ~~~~~~^~~~~~~~~~~~~~