Compilare: main.cpp: In function 'int main()': main.cpp:121:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (i = 0; i<v[nod.x].size(); i++) ~^~~~~~~~~~~~~~~~ main.cpp: In function 'char next()': main.cpp:18:29: 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, bsize, fin); ^