Compilare: main.cpp: In function 'void _union(int, int)': main.cpp:73:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses] if (x!=y) ^ main.cpp: In member function 'char InParser::read_ch()': main.cpp:14:29: 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); ^