Compilare: user.cpp: In function ‘void dfs1(int)’: user.cpp:19:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<a[nod].size();i++) ^ user.cpp: In function ‘void dfs2(int, int)’: user.cpp:32:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(i=0;i<b[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:92:23: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(j<=N) if(sol[j+N]==0) sol[j+N]=c1; ^ user.cpp:102:19: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(j<=N) if(sol[j+N]==0) sol[j+N]=2; ^