Compilare: main.cpp: In function 'int main()': main.cpp:85:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<vec[x].size();++i) ~^~~~~~~~~~~~~~ main.cpp:111:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(k and ind<vec[0].size()) ~~~^~~~~~~~~~~~~~