Compilare: main.cpp: In function 'void dfs(int)': main.cpp:20:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ main.cpp: In function 'void dfs2(int)': main.cpp:112:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<fr[x].size();i++) ~^~~~~~~~~~~~~ main.cpp:127:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) ~^~~~~~~~~~~~ main.cpp:106:11: warning: unused variable 'j' [-Wunused-variable] int i,j; ^