Compilare: main.cpp: In function 'void build()': main.cpp:52:41: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare] 52 | #define FOR(i, a, b) for(int i = (a); i <= (b); ++i) | ^ main.cpp:104:9: note: in expansion of macro 'FOR' 104 | FOR(i, 1, pattern.SZ - 1) | ^~~