Compilare: main.cpp: In function 'void dfs(int)': main.cpp:13:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i=0;i<l[nod].size();i++){ ~^~~~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:43:37: warning: ignoring return value of 'size_t fread(void*, size_t, size_t, FILE*)', declared with attribute warn_unused_result [-Wunused-result] fread (buff , 1 , 2000000 , fin); ^