Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:14:36: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[cur].size(); i ++) { ^ user.cpp: In function ‘void dfs2(int, int)’: user.cpp:24:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v2[cur].size(); i ++) { ^ user.cpp: In function ‘int main()’: user.cpp:34:12: warning: unused variable ‘k’ [-Wunused-variable] int n, k; f >> n; ^