Compilare: main.cpp: In function 'int main()': main.cpp:45:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < l.size() - 1; i++) ~~^~~~~~~~~~~~~~ main.cpp:53:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j = i + 1; j < l.size(); j++) ~~^~~~~~~~~~ main.cpp:83:30: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < sol.size(); i++) ~~^~~~~~~~~~~~