Compilare: main.cpp: In function 'bool Check_Match(int)': main.cpp:15:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) { ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:34:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < a.size(); ++i) { ~~^~~~~~~~~~