Compilare: main.cpp: In function 'int main()': main.cpp:30:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[x].size();i++) ~^~~~~~~~~~~~ main.cpp:34:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<un.size();i++) ~^~~~~~~~~~ main.cpp:19:16: warning: unused variable 'j' [-Wunused-variable] {int i,c,c1,c2,j; ^ main.cpp: In function 'void bfs(int, int)': main.cpp:55:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[x.el].size();i++) ~^~~~~~~~~~~~~~~