# Based on https://rosettacode.org/wiki/Modular_arithmetic#Python # Licensed under GFDL 1.2 https://www.gnu.org/licenses/old-licenses/fdl-1.2.html import operator import functools @functools.total_ordering class Mod: __slots__ = ['val','mod'] def __init__(self, val, mod): if not isinstance(val, int): raise ValueError('Value must be integer') if not isinstance(mod, int) or mod<=0: raise ValueError('Modulo must be positive integer') self.val = val % mod self.mod = mod def __repr__(self): return 'Mod({}, {})'.format(self.val, self.mod) def __int__(self): return self.val def __eq__(self, other): if isinstance(other, Mod): self.val == other.val elif isinstance(other, int): return self.val == other else: return NotImplemented def __lt__(self, other): if isinstance(other, Mod): return self.val < other.val elif isinstance(other, int): return self.val < other else: return NotImplemented def _check_operand(self, other): if not isinstance(other, (int, Mod)): raise TypeError('Only integer and Mod operands are supported') def __pow__(self, other): self._check_operand(other) # We use the built-in modular exponentiation function, this way we can avoid working with huge numbers. return __class__(pow(self.val, int(other), self.mod), self.mod) def __neg__(self): return Mod(self.mod - self.val, self.mod) def __pos__(self): return self # The unary plus operator does nothing. def __abs__(self): return self # The value is always kept non-negative, so the abs function should do nothing. # Helper functions to build common operands based on a template. # They need to be implemented as functions for the closures to work properly. def _make_op(opname): op_fun = getattr(operator, opname) # Fetch the operator by name from the operator module def op(self, other): self._check_operand(other) return Mod(op_fun(self.val, int(other)) % self.mod, self.mod) return op def _make_reflected_op(opname): op_fun = getattr(operator, opname) def op(self, other): self._check_operand(other) return Mod(op_fun(int(other), self.val) % self.mod, self.mod) return op # Build the actual operator overload methods based on the template. for opname, reflected_opname in [('__add__', '__radd__'), ('__sub__', '__rsub__'), ('__mul__', '__rmul__')]: setattr(Mod, opname, _make_op(opname)) setattr(Mod, reflected_opname, _make_reflected_op(opname)) class Uint8(Mod): __slots__ = [] def __init__(self, val): super().__init__(val, 256) def __repr__(self): return 'Uint8({})'.format(self.val) class Uint16(Mod): __slots__ = [] def __init__(self, val): super().__init__(val, 65536) def __repr__(self): return 'Uint16({})'.format(self.val) class Uint32(Mod): __slots__ = [] def __init__(self, val): super().__init__(val, 4294967296) def __repr__(self): return 'Uint32({})'.format(self.val) class Uint64(Mod): __slots__ = [] def __init__(self, val): super().__init__(val, 18446744073709551616) def __repr__(self): return 'Uint64({})'.format(self.val) def simulate_int_type(int_type: str): if int_type == 'uint8_t': return Uint8 if int_type == 'uint16_t': return Uint16 if int_type == 'uint32_t': return Uint32 if int_type == 'uint64_t': return Uint64 raise ValueError('unsupported integer type: {}'.format(int_type))