Compilare: main.cpp: In function 'void Read()': main.cpp:28:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < a.size(); ++ j ) { ~~^~~~~~~~~~ main.cpp: In function 'bool Check(int, std::vector<int>)': main.cpp:38:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < ind.size(); ++ i ) { ~~^~~~~~~~~~~~ main.cpp:39:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (val[ ind[ i ] ].size() <= K) return false; ~~~~~~~~~~~~~~~~~~~~~~~^~~~ main.cpp:44:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < ind.size(); ++ i ) { ~~^~~~~~~~~~~~