Compilare: main.cpp: In function 'void dfs_down(long long int, long long int)': main.cpp:12:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp: In function 'void dfs_up(long long int, long long int)': main.cpp:39:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp:60:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0 ; i < v[nod].size() ; i++){ ~~^~~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:88:27: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%lld",&n); ^ main.cpp:90:52: warning: ignoring return value of 'int fscanf(FILE*, const char*, ...)', declared with attribute warn_unused_result [-Wunused-result] fscanf (fin,"%lld%lld%lld%lld",&x,&y,&a,&b); ^