Compilare: main.cpp: In function 'int main()': main.cpp:30:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<a[v[i]].size(); j++) ~^~~~~~~~~~~~~~~ main.cpp:42:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(j=0; j<a[minn.second.second].size(); j++) ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~