Compilare: main.cpp: In function 'void dfs(int)': main.cpp:15:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[nod].size(); ++i) { ~^~~~~~~~~~~~~~ main.cpp: In function 'void dfs2(int)': main.cpp:24:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<r[nod].size(); ++i) { ~^~~~~~~~~~~~~~ main.cpp: In function 'void dfs3(int, int)': main.cpp:37:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[nod].size(); ++i) { ~^~~~~~~~~~~~~~ main.cpp:36:14: warning: variable 'found' set but not used [-Wunused-but-set-variable] bool found=false; ^~~~~ main.cpp:50:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0; i<g[nod].size(); ++i) { ~^~~~~~~~~~~~~~