Compilare: main.cpp: In function 'int main()': main.cpp:36:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0; j<list[i].size(); j++) { ~^~~~~~~~~~~~~~~ main.cpp:33:16: warning: 'maxx' may be used uninitialized in this function [-Wmaybe-uninitialized] for(int i=1; i<=maxx; i++) { ~^~~~~~