Compilare: main.cpp: In function 'int main()': main.cpp:30:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(sol.size()!=n) ~~~~~~~~~~^~~ main.cpp:33:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<sol.size(); j++) ~^~~~~~~~~~~ main.cpp:42:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<sol.size(); i++) ~^~~~~~~~~~~