Compilare: main.cpp: In function 'void combi(int)': main.cpp:33:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(vecc.size()==k){ ~~~~~~~~~~~^~~ main.cpp:34:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vecc.size();i++) fout << vecc[i] << ' '; ~^~~~~~~~~~~~ main.cpp:37:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(vecc.size()<k) ~~~~~~~~~~~^~