Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:23:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<a[x].size();i++) ^ user.cpp: In function ‘void dfs1(int)’: user.cpp:36:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<b[x].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:70:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int j=0;j<c[psol].size();j++) ^