Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:30:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<V[nod].size();i++){ ^ user.cpp: In function ‘int main()’: user.cpp:47:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(Sol.size()!=n-1){ ^ user.cpp:52:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<Sol.size();i++){ ^ user.cpp: In function ‘void read()’: user.cpp:19:27: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&n,&m); ^ user.cpp:23:31: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(f,"%d%d",&x,&y); ^