Compilare: user.cpp: In function ‘void dfs(int)’: user.cpp:50:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[x].size();i++) { ^ user.cpp:48:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,y; ^ user.cpp: In function ‘int main()’: user.cpp:77:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,x,y; ^ user.cpp:78:35: warning: ignoring return value of ‘FILE* freopen(const char*, const char*, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] freopen("egal.out","w",stdout); ^ user.cpp: In member function ‘void instream::advance()’: user.cpp:39:48: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input_file); ^ user.cpp: In constructor ‘instream::instream(const char*)’: user.cpp:17:44: warning: ignoring return value of ‘size_t fread(void*, size_t, size_t, FILE*)’, declared with attribute warn_unused_result [-Wunused-result] fread(buffer,SIZE,1,input_file); ^