Compilare: main.cpp: In function 'bool Solve(int)': main.cpp:17:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (freq.size() <= K) ~~~~~~~~~~~~^~~~ main.cpp:29:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (freq.size() <= K) ~~~~~~~~~~~~^~~~ main.cpp: In function 'int main()': main.cpp:55:23: warning: 'answer' may be used uninitialized in this function [-Wmaybe-uninitialized] fout << answer << "\n"; ^~~~