Compilare: main.cpp: In function 'bool pairup(int)': main.cpp:80:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[node].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp:89:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < v[node].size(); i++) ~~^~~~~~~~~~~~~~~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:19:29: 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, 4096, fin); ^