Compilare: user.cpp: In function ‘void dfs(int, int)’: user.cpp:43:11: warning: unused variable ‘vec’ [-Wunused-variable] int p,vec; ^~~ user.cpp: In function ‘long long int getint()’: user.cpp:16:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^ user.cpp:21:40: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buf,maxb,1,fin),ptr=0; ^