Compilare: user.cpp: In function ‘void updatearb()’: user.cpp:69:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,a,b,x,y; ^ user.cpp: In function ‘void dfs(int)’: user.cpp:106:28: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i=0;i<v[nod].size();i++) { ^ user.cpp: In function ‘int main()’: user.cpp:120:11: warning: unused variable ‘j’ [-Wunused-variable] int i,j,a,b,o; ^ user.cpp: In member function ‘void inreader::advance()’: user.cpp:38:51: 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 ‘inreader::inreader(const char*)’: user.cpp:16:47: 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); ^