Compilare: main.cpp: In function 'int main()': main.cpp:23:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] { for(int j=0; j<sol[i-2].size(); j++) sol[i].push_back(sol[i-2][j]); ~^~~~~~~~~~~~~~~~ main.cpp:26:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<sol[i-1].size(); j++) sol[i].push_back(sol[i-1][j]); ~^~~~~~~~~~~~~~~~ main.cpp:29:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol[n].size(); i++) ~^~~~~~~~~~~~~~