Compilare: main.cpp: In function 'void bfs()': main.cpp:15:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ~^~~~~~~~~~~~ main.cpp: In function 'void bell_ford()': main.cpp:38:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ~^~~~~~~~~~~~