Compilare: user.cpp: In function ‘int main()’: user.cpp:53:26: warning: array subscript has type ‘char’ [-Wchar-subscripts] b = ((b - (v[B[i]] * p) % mod + mod) * base + v[B[i + m + 1]]) % mod; ^ user.cpp:53:69: warning: array subscript has type ‘char’ [-Wchar-subscripts] b = ((b - (v[B[i]] * p) % mod + mod) * base + v[B[i + m + 1]]) % mod; ^ user.cpp:57:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] FOR(i, 0, sol.sz() - 1) ^ user.cpp:4:42: note: in definition of macro ‘FOR’ #define FOR(i, x, y) for(int i = x; i <= y; ++i) ^