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; ^