Compilare: main.cpp: In function 'void bfs()': main.cpp:15:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[k].size();i++) ~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:25:1: warning: this 'for' clause does not guard... [-Wmisleading-indentation] for(int i=1;i<=n;i++) ^~~ main.cpp:27:5: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'for' return 0; ^~~~~~