Compilare: main.cpp: In function 'int main()': main.cpp:38:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vec[x].size();) ~^~~~~~~~~~~~~~ main.cpp:56:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int k=0;k<vec[x].size();++k) ~^~~~~~~~~~~~~~ main.cpp:65:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=1;j<=vec[x].size();++j) ~^~~~~~~~~~~~~~~