Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:56:39: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i=0;i<neighbors[nod].size();i++) ^ user.cpp: In function ‘int main()’: user.cpp:16:29: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&N,&M); ^ user.cpp:19:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&val[i]); ^ user.cpp:24:34: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d",&tata[i]); ^ user.cpp:46:33: warning: ignoring return value of ‘int fscanf(FILE*, const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] fscanf(fin,"%d%d",&X,&Y); ^ user.cpp:36:14: warning: ‘root’ may be used uninitialized in this function [-Wmaybe-uninitialized] dfs(root); ^