Compilare: main.cpp: In function 'void bfs(int)': main.cpp:157:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<a[na].size(); i++) ~^~~~~~~~~~~~~ main.cpp:159:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<v[na].size(); i++) ~^~~~~~~~~~~~~ main.cpp: In member function 'char InParser::read_ch()': main.cpp:14:38: 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); ^